Layering is back, beanies are big, matchy-matchy just got matchy-matchier and burgundy, we mean 'madder carmine', is everywhere: just a snippet of what we've learned from the collections in New York

When New York fashion week controversially upped and moved its position in the catwalk season running order, so that rather than happening after London, Milan and Paris it took an early slot before any of the others, the idea was to give the city's fashion scene some breathing space out of the shadow of Europe. No longer could London claim New York was copying its ideas; no longer would buyers arrive weary.

It was a good plan, and for many seasons it worked; this week, however, it backfired. New York isn't over. Shows go on until late Thursday. But so far, despite some strong shows and very nice clothes, it has felt like a cocktail party that passes without incident, ending with taxis called at a civilised hour rather than a highly charged all-back-to-mine rave-up.

A few examples: Alexander Wang's show was strong, but the drop-waists and softly voluminous silhouettes – along with the choice of the ticketing hall of the Cunard building as a venue – framed it clearly as a precursor to Wang's much-anticipated debut at Balenciaga next week, more a wave to Paris than a bow to New York. And then there was Oscar de la Renta, colossus of American fashion, whose show was dominated by chatter about his infamous intern from across the Atlantic, John Galliano. More than anything else, the rescheduling of Marc Jacobs' mainline show to a graveyard slot on Valentine's night – a delay caused by the non-arrival of fabrics following the Nemo blizzard – set the week off-kilter, as if someone had moved Christmas Day to 30 December at a few days' notice, leaving you unsure when to don your party hats and pull your crackers.

There was something inevitable about the fact that the undisputed model of the week was a Brit. If there's one thing you need to do to be on-trend right now, it is to become obsessed with Cara Delevingne, whose caterpillar eyebrows stomped down almost every catwalk this week. With a Twitter feed featuring snaps of her snogging Rita Ora and eating packets of Monster Munch, she did her level best to liven up New York.

The next big thing: Menswear fabrics

Last season's big womenswear noise was around a mannish silhouette; for autumn, it's all about menswear fabrics. Tommy Hilfiger gave preppy style a kooky Hogwarts twist by layering up houndstooth, Prince of Wales checks, and pinstripes. See also: windowpane plaid at Victoria Beckham and Philip Lim, houndstooth at Thom Browne, herringbone at DKNY and J Crew.

The comeback: Layering

Remember how we were all, "layering's so over, it's all about the crisp simple pieces"? Well, scratch that. Your outfit isn't happening unless there's a shirt collar and tails poking out at neckline and cuff (just one symptom of the general Céline-ification of the modern runway). This is Philip Lim; for a cuter, cleaner take on the same idea see J Crew.

The accessory: The beanie

It felt symptomatic of the way this New York fashion week never quite caught fire that the much-hyped grunge revival was not as clear a catwalk trend as expected. The exception was the beanie, the undisputed catwalk and streetstyle key look of the week, seen everywhere from Victoria by Victoria Beckham to Tommy Hilfiger.

The retro trend: 70s glam

"It's not about going to a party, it's about life as a party," said Diane von Fürstenberg backstage. Who's going to argue with that? Von Fürstenberg and Marc by Marc Jacobs both reached back to a glorious era of NYC history, the late 70s, to inject some feelgood rock'n'roll glamour into the week.

The new matchy-matchy: Matchy-matchy-matchy-matchy

Seriously. At DKNY, a pink-tinged leopard sweater was worn with a skirt, bag and shoes – all in the same print. Fashion is about finding new ways to make matching modern, right now. At J Crew there was a new kind of trouser suit: matching sleek, tailored tracksuit bottoms and sweatshirt in upscale fabric. Just don't call it a tracksuit.

The silhouette: The round shoulder

If you change one thing, change this: the sharp shoulder is dead. It doesn't really matter whether you take the Alexander Wang route (a Paul Poiret, kimono-ish silhouette) or the sportier, DKNY/Victoria Beckham/J Crew raglan sleeve route. What matters is that the shoulder is soft and rounded, not Gaga-sharp. Got it?

The name to drop: Thom Browne

He is known for two fashion moments: instigating the cropped-trouser trend as a hipster-menswear motif, and dressing Michelle Obama in a necktie-inspired dress for the inauguration. His show this season confounded those who expected him to use the inauguration as a commercial springboard: all exaggerated silhouettes and theatrics, it was bonkers and utterly brilliant.

The new phrase: Madder carmine

I won't lie, I had to look it up. Turns out, madder carmine is a purplish red. In the parlance of the British school uniform, we know it as burgundy. Burgundy is making an early attempt to oust navy this season, cropping up everywhere from Victoria by Victoria Beckham to Diane von Fürstenberg.

From the Duchess of Cambridge and Samantha Cameron to Mary Berry and Coleen Rooney, Zara is now everyone who is anyone's favourite high-street fashion label

Say you were to walk into a London fashion week catwalk show today and order everyone to undress (this is hypothetical, by the way – please don't), an inventory of which high-street label is most worn by the fashionables would, I suspect, surprise many. Topshop would be well represented, naturally, especially the tuxedo trousers, and the so-on-trend dungarees, and the JW Anderson knits (the high-street fashionista's answer to a Jonny Saunders). Cos and Whistles would be punching well above their retail square footage. But the name you'd find over and over again, from the front row to the standing section, in shoes and tailored jackets, in subtle navies and greys as well as this season's lemon sherbet bright? Zara.

Zara has become everyone's favourite fast fashion hit, and the watercooler fashion name to drop. These days, it provides a rich seam of instant small talk between women who like clothes, crossing boundaries of age, class and style. The Duchess of Cambridge wore a blue Zara dress the day after wearing McQueen for her wedding. Coleen Rooney mixes Zara with her designer wardrobe. Mary Berry (77) and Selena Gomez (20) have both worn Zara on TV recently. Samantha Cameron wears Zara to Conservative party conference; the Saturdays wear Zara to go clubbing.

Last month, invited to a smart industry dinner during the Paris haute couture shows, Grazia's senior fashion features editor, Katherine Ormerod, chose from her packed wardrobe her most recent trophy purchase: a striking, broad-striped monochrome Zara blouse. It was "super-chic and on-trend, and it cost only £39.99. But my smugness was soon dented when a French journo arrived wearing the exact same thing, and then an Italian PR in the same blouse in a different colourway. There were only 20 of us around the table and I was obviously – cringingly – seated next to my twins."

The Zara-twin moment has become a frequent fashion week banana skin. Nicola Rose, fashion director of Red magazine (most recent Zara purchases: cream cable-knit sweater with back zip, black kitten heels, sweat top), has a wardrobe stocked with Marni and Miu Miu, but says, "All the fashion insiders top up their wardrobe with something from Zara." Her colleague Emily Gegg, Red's executive fashion director (most recent purchase: black sleeveless blazer), calls Zara "the fashion industry's staple".

Zara's ascendancy to fashion's top table began towards the end of the last decade, as fashion changed direction away from dresses and towards separates. A gradual tidal pull away from the stand-alone trophy dress and towards a wardrobe based on jackets, blouses, trousers and skirts worked in Zara's favour for two reasons. First, the store was among the first on the high street to master production of the new structured jackets at an affordable price. Lily Russo, shopping editor of Grazia, pinpoints the season "when Balmain first sent models down the catwalk with sharp-shouldered rock chick blazers" as the moment Zara got a grip on the fashion zeitgeist.

But there is a second and more fundamental reason the current mood of fashion – in which our wardrobes are steered by the chic, understated, piece-by-piece minimalism pioneered by Stella McCartney and Phoebe Philo at Céline– has benefited Zara. Zara has a unique design model, carefully calibrated to be responsive to what the customer is buying in store. Every single garment on sale in Zara is designed by a 350-strong team at its parent company, Inditex, based in La Coruña, Spain. Between them, they produce more than 18,000 creations a year, from shoes to sweaters, from T-shirts to coats. Although some pieces are manufactured in Morocco or China, most are made in Spain, a proximity that allows for the fastest possible turnaround time.

"This fashion-creating cycle has nothing to do with the catwalk cycles, which show very different proposals of trends several months in advance," Jesus Echevarria, Zara's communications director, tells me. "Zara reacts directly to the customers' tastes for specific trends created by the in-house team. This is the real inspiration for the design team: the choices that everyday customers take in the stores."

Zara's secret weapon is the way in which information harvested on the shopfloor is put to use. If a deep V-neck sweater is selling better than a scooped one, the design team will set to work producing variations on the V-neck. Sales of these will be monitored, and the most successful produced in quantity. "This information reaches the design team, which reacts always with only one thing in mind: what the customer is really wanting. They must be in the skin of the customer. All the organisation is structured towards this aim."

If Echevarria is bullish to the point of evangelism about his business model, the statistics back him up: last year, Zara posted profits of £1.3bn. Amancio Ortega, Inditex's owner, recently leapfrogged Warren Buffett to become the fifth richest man in the world.

Zara's newest and smartest London store, facing the gigantic Marks & Spencer flagship at Marble Arch, is a notably different shopping experience from any of its Oxford Street competitors. The music is quiet and anonymous. There are few images of models wearing the clothes; instead, there are endless mirrors. The atmosphere is less about a social experience and more akin to being inside an enormous, upmarket walk-in wardrobe. It is the perfect environment for a store such as Zara, whose success is built on understanding the shopping impulses of the customer. An "intimate environment in which women are encouraged to assemble their own outfits" is how Inditex describes the new store. On a weekday afternoon, the customers are mostly women shopping alone, although a few are with friends or grown-up daughters. There are mums in parkas pushing sleeping toddlers in buggies, and women in suits with one eye on the time. A woman with a taupe-coloured Céline handbag is browsing next to one clutching two Primark carriers.

Zara's lofty insistence that it does not follow the catwalk is not entirely borne out by the shopfloor. Only the day before, I was admiring photos of the houndstooth check separates designed by Raf Simons for the Christian Dior pre-fall collection, and here, by remarkable coincidence, are a pair of houndstooth cropped trousers (£39.99). An abundance of thick black-and-white striped pieces closely echoes the look seen on the Marc Jacobs catwalk; a black cocktail dress with a stiffened waterfall ruffle is a striking reminder of the current Givenchy collection. A press officer for a prestigious Parisian fashion house told me, on strict condition of anonymity, that she is always pleased when Zara stocks variations on her brand's collection, because even at a discount she can't always afford the real thing – and Zara, she says, "even fools people in Paris".

For key looks, Zara will sell multiple variations on a theme. For instance, I find myself looking at a rack of blazers, in panels of matt black and shiny black viscose. Some have subtle textured navy panels, some have piped edges. Some have flat collars, or notched lapels; some have satin tuxedo detailing. Not since the days of visiting the dressmaker have women's individual preferences been so well catered for at mass market level. In recognising these small differences, Zara flatters the customer's taste. And choice is a smart selling tactic: after flicking through the racks for a few minutes, I realise I have stopped wondering if I should try on a jacket and started wondering which jacket I should try on. (For the record, I bought the one with navy panels. In three outings, it has racked up compliments in double figures.)

There is, of course, a good deal of what I would nontechnically describe as tat. A black lace dress that is cheap and flammable; a street market-esque printed T-shirt. Nicola Rose won't touch the trousers, because "the fabrics just don't work for me. I am very particular about wools and cottons." And the size range can be narrow. Lily Russo says, "I am a size 12 and sometimes a 'large' skirt or trousers doesn't fit. My sister is a size 16 and it would be great if they catered for that size also."

A week and a half later, I make a return trip to Zara. The wide monochrome stripes that dominated the first floor last time have been superseded by abbreviated slim trousers, boyish blazers, silky blouses: a look that closely echoes Hedi Slimane's first collection for Saint Laurent, which recently arrived half a mile away on Bond Street. My navy-panelled blazer has vanished, and I am instantly gratified that I bought it on first sight. (Zara shoppers learn this lesson fast, which helps swell coffers.)

For a generation who have grown used to grazing on fast fashion like hummingbirds on sugar, Zara is addictive. I popped in only to have a quick scout; five minutes later, I'm back in the changing rooms. I'm hooked. Aren't we all?

The youngest Geldof girl tries out the latest trends and talks family, fashion and her band, Violet

When Pixie Geldof's band started getting written about last year, several journalists reported that the band name, Violet, was the middle name of the famous lead singer, which is not true. The name Violet was, as it happens, taken in homage to the Hole song of that name; Pixie Geldof's middle name is, technically, Pixie. (Her full name is Little Pixie Geldof. Take a moment.) It was just one of many millions of snippets of assumption and misinformation that snowball unchecked on the internet, but there is something telling about it: however much Pixie might like to keep her being in Violet distinct from her being the daughter of Bob Geldof and Paula Yates, the world can't or won't separate the two.

Violet have released a couple of singles, played some small-ish gigs, and – so far – been pretty warmly welcomed by reviewers. When I arrive to meet Pixie, the band are rehearsing in a tiny Hackney studio for a gig that night at the Notting Hill Arts Club. The boys in the band are standard-issue east London musicians (fishermen's sweaters, beards, sarcasm); Pixie is a goofy mix of girlish ingenue and frontman swagger. She wears her hair in a delicate, Jean Seberg crop, but is dressed in a huge green parka of Gallagher proportions; her fierce sandals are sky-high, but her speaking voice has something of her dad's gruffness. ("I sound like a really nasal bloke," is how she puts it, cheerily.)

Geldof writes Violet's songs, all but one of which are about heartbreak. On What You Gave To Me, she sings, "I want to hear you say/That you're not coming back, and it won't be OK/While I drink a bottle of wine/A little closure." She is very open about the fact that the songs are about her first relationship, and subsequent broken heart, five years ago. She tells me that apart from Y.O.U, which is about her current relationship, the songs are "about the torment of first love. I was 17, and I was just broken up. I wrote songs because I thought, maybe he'll hear them and love me again, but also because I didn't know what else to do with myself. I remember feeling like every single part of my body was physically hurting."

Paula Yates, Pixie's mother, never recovered her equilibrium after the death of her lover Michael Hutchence and died of a heroin overdose three years later, on Pixie's 10th birthday. It was a shocking final act to the scandal of the affair that ended her marriage to Bob Geldof.

While Pixie chats about teenage heartbreak, she fiddles with her mug and I can see, on the inside of her left wrist, a tattoo of her mum's name; on her other arm is inked, in gothic script, "What will survive of us is love." Listening to her talk, it is difficult not to hear the echo of how heartbreak left this little girl without a mother. Having grown up defined in the public eye by a tragedy she was too young to understand, writing her own lyrics about first love and loss is perhaps a way for Pixie to take control of her own public image. And yet hers is a backstory that Pixie knows "will never go away. And I don't want it to – I'm proud of my family. They are wonderful. I've got nothing to be ashamed of. The people who should be ashamed are the people who talk about it as if it's some kind of a black mark against our name. I've had tough parts of my life, but who hasn't? It's who I am. It's fine.

"At some point, hopefully, people will start referring to me as a singer," she says. "I'm not the world's best singer, but I can sing. I'm not Bob Dylan, but I can write a song. And if you don't like it, that's absolutely fucking fine by me. Just don't listen, right?" The Geldof chin juts out and she looks, and sounds, very much her father's daughter. Her dad "never discouraged me from music, but he always made it very clear that it was hard and that one in a million people make it and that nowadays no one makes any money, anyway. He would have preferred me to get a degree, but he's supportive because he knows this is what I'm really about."

During her teenage years, Pixie "wanted everything to be very dark". She was obsessed with Hole, Nirvana, Mazzy Star ("The saddest music in the world, but also the most beautiful") and from there with country music of the 50s and 60s "that bands like Nirvana were so influenced by. Those two kinds of music go hand in hand. I like the women best. Patsy Cline and Tammy Wynette: those are my heroines. When I'm sad, I just want to cry it out. Tammy understands, you know?"

A wild-child phase when she and her sister Peaches were christened the Boomtown Brats was, she says, exaggerated by the tabloids. "When I was 16, I went out a bit, but it was mostly to the pub on my street. It really wasn't all that shocking. I mean, I never missed curfew – I was always home by 10. With my dad, it was all about trust. He expected good grades and homework done and curfew met. When I was 16, he was like, if you're home by 10 and it's not every night, OK. But I knew I had to keep my end of the deal. It was an important lesson."

These days, she says, "I don't even really drink. I don't like the taste of alcohol. I'm really boring. When I'm with the boys in the band, they'll be like, 'Shots o'clock!' and I'm all, 'Night, I'm off to bed.'" (I can't help suspecting that if this is true, her teen partying phase was perhaps more intense than she now admits. You don't get to be that jaded with partying at 22 otherwise, do you?) She lives in Clapton with her boyfriend George, drummer in These New Puritans, her best friend Ashley Williams, a rapidly up‑and‑coming fashion designer who counts Rihanna among her fans, and Buster Sniff, a long-haired chihuahua. For Pixie's birthday, George bought her a jukebox loaded with her favourite music. ("So we wake up to Dolly every morning. How sick is that?")

Pixie's eldest sister, 30-year-old Fifi Trixibelle, lives in south London; Peaches, who is just 18 months older than Pixie, lives in Whitechapel with her husband and a baby son who continues the family tradition of kooky baby names by being called Astala. Their youngest sister Tiger (full name: Heavenly Hiraani Tiger Lily), who was adopted by Geldof after being orphaned by the deaths of Hutchence and Yates, "is still at home with Dad. I called home the other night and Dad said he was taking Tiger to see the Stones. I was like, 'Dad, it's a school night!' And he's like, 'Yeah, but she's got to see the Stones.' And he's right." Sixteen-year-old Tiger is "a total sweetheart. I was worried she would turn out all, you know, rock, but she hasn't. She's very well behaved and a lovely person, very kind. And so beautiful. I'm watching her like a hawk, that one."

The badass singer previously known as Bat for Lashes talks about albums, intelligence and her evolving image

Last year, while she was getting ready to release her third album, Natasha Khan – better known by her nom de pop, Bat for Lashes– cut her long, thick, dark, wavy hair into a neat bob. This was universally taken to be a sign, since Khan's hair had previously been styled around motifs of wilderness, madness, rebellion. Sometimes it was long and loose, all the better for a pagan whirl on stage; sometimes it was topped with a Native American-style feather headdress. For a while there had been a glittery headband, motif of those ultimate good-time girls, the flappers; once there were two tiny white feathery swans nestled in the dark hair in a Björkian echo. The bob, it was assumed, heralded a new clean-cut, grown-up persona.

"Actually, I cut my hair because I was getting really bad split ends," Khan says, and bursts out laughing over her vegetarian focaccia. This vegetarian focaccia has already caused a crisis in the Victoria Park deli where Khan has asked to meet. The success of her albums – Fur And Gold in 2006, Two Suns three years later and now The Haunted Man– has seen her crowned as art-pop royalty, Victoria Park's version of the Duchess of Cambridge. When it turned out there were no avocados for the salad Khan ordered, a waiter was hastily sent out to buy some. He returned, empty-handed and aghast, reporting that "there are literally no avocados in the village", his stricken expression neatly encapsulating how mightily things have changed in the E9 postcode and how much hipster boys (and girls) crush on Khan.

The Haunted Man, released just before Khan's 33rd birthday, is, she says, "very much the woman of my album trilogy. The first album is little-girl Natasha – suburbia and horror films and that crazy internal life of adolescence. The second was me going out into the world, having an incredible time but kind of out of my depth in love and hate and craziness. With the third one, I had calmed down a bit, stopped flinging myself around between dramas. It's more subtle. It's about the complexity and nuance of how a woman in her 30s feels. All these possibilities: feeling broody or maternal or nurturing or sexual or powerful or angry or frightened or forgiving."

Khan may be older and wiser, but she is still (as she puts it succinctly) "badass". Her bob, while undeniably no-nonsense, is less Michelle Obama than Zelda Fitzgerald. On the cover of The Haunted Man, she appears naked, with a naked man slung over her shoulders. The idea came from a photograph by Ryan McGinley, in which a naked girl is carrying a wolf in the same pose, which Khan came across in a book halfway through the making of The Haunted Man. "This album is about relationships, about men and women, and I imagined the man as a soldier, or a sailor I had dragged in from the sea." She approached McGinley about revisiting the idea, and he agreed.

There is a magical element to the cover, this slender girl with a man slung over her shoulders, that plays into the tendency to file Khan under kooky. But despite the vaguely mystical image that hangs around her, she is entirely clear-eyed about the difficulty of her position in the musical marketplace. "The record company doesn't know what to do with me, because I'm not a Lily Allen, but I'm not really an indie artist, either. All the best artists have been in the middle. David Bowie worked with Brian Eno and dressed up in extraordinary clothes, but he was also a brilliant songwriter who captured the thoughts of a generation. He was hugely successful, without compromise. So, that's the dream. But you only have to turn on the radio to recognise how much the musical landscape has changed." Sometimes, she says, it's tempting to "get a big remix done, or whatever. But it comes down to an ethical decision about whether it feels right, and I know selling out won't bring me happiness."

The Bowie analogy is a telling one. It frustrates Khan when the visual and storytelling elements to her performance are patronisingly batted away as the vague hippy-dippiness of an art-school chick. "In the music industry, intelligence in women is undervalued. What pisses me off is that I write my own music, do the production myself, then get written about as a singer who gets dressed up. In the art world there are these extraordinary, vivid, strong female personas – Louise Bourgeois, Cindy Sherman, Yoko Ono – but music won't allow women the space for that."

For her most recent tour, Khan took sketches of her own designs to her dressmaker: Martha Stewart dancewear shapes, in monochrome, with graphic lines. "The look was conceived in a more deliberate way. Before, when I was in New York with my boyfriend, we'd make an art project out of going round the thrift shops, finding these amazing juxtapositions, like gold antlers with a pair of boxing gloves." Today, she is wearing a vintage fake fur jacket she found in LA, an Anthropologie jacket and a YMC jumper in Pepto-Bismol pink. And she is collaborating with Australian fashion duo Romance Was Born, who are making outfits for her next tour. I am quizzing her about these stage clothes and Khan, in her typically left-field way, starts telling me she has a new boyfriend, an actor. "When I look at this man, who I've just fallen in love with, it's like looking at a rainbow. So when I'm on stage, I just want to wear rainbows. I said to [Romance Was Born designers] Anna and Luke that in my head I can see a white cape with gold edging and cuffs, and maybe a rainbow onesie underneath? And they're like, cool, no problem, we'll sort it."

She looks suddenly radiant, smiling at the thought of the actor, the rainbows, the designers who unblinkingly catch her curve balls. "The impulse for everything comes from a very personal place," she adds. You don't say.

Singer's collection was never about the clothes, which are bright and tight, but the intrigue and controversy that surrounds her

Here's a thing that young women do, on a Saturday night, when they've had a few drinks. A rap song comes on with rude lyrics, and emboldened by a Saturday night fever which is as ancient as they are young, they sing along, gleefully emphasising all the swearwords, miming rap-swagger with extra lip gloss. It's a wild-side thing, a flirting-with-danger thing. At Rihanna's London fashion week catwalk show on Saturday night, soundtracked by a track by A$AP Rocky which I shall leave unspecified since neither the title nor any of the first 10 lines are printable, the young British supermodels-of-the-hour Cara Delevingne and Jourdan Dunn were doing it in the front row – and when the show finished, they stood up, holding hands, and danced backstage, rap-miming every step of the way.

We'll come to the clothes on the catwalk – part of a 120 piece Rihanna collection which goes on sale in River Island in two weeks' time – later. Let's be honest: the clothes were never going to be the main event here. The intrigue and controversy that surrounds Rihanna these days is such that even when she releases an album, or wins an award, the music isn't the main event. Whether she's selling music or perfume or hotpants it is her body, her lifestyle – and more than anything her relationship with Chris Brown, with all the attitudes and issues that raises – which are the story.

The spirit of mouthy, dare-you swagger that pulsed through the speakers and infiltrated the Frow on Saturday night will be what sells these clothes. If you are 18, 20, 22 years old, then Rihanna represents your darker, badder side. (That she herself seems sometimes to be at the mercy of her own dark side complicates the whole thing further.) The staging of the event – in a bleak warehouse, nonsensically late, ludicrously crowded – bore all the hallmarks of the treat-them-mean, keep-em-keen school of public relations with which Rihanna's people seem to be well versed (see: the Rihanna jet). There was, however, plenty of champagne and vodka. Sobriety is not what this brand stands for.

The clothes? They are bright, and tight, and aggressively sexual. They require abs of steel and are mostly incompatible with the wearing of bras. Their target audience is young, and would interpret brazen as a compliment. Unlike collaborations in which fashion designers bring a new visual language into a store – Martin Margiela for H&M, say – the Rihanna for River Island range is very recognisably River Island. What the Rihanna label brings is not extra fashion content, but personality and attitude.

London fashion week sees good old-fashioned desirability from retailer, glamour from L'Wren Scott and elegance from Mulberry

The traditional catwalk show – a small, elite group of people viewing clothes that will be accessible and affordable to a small, elite group of people – is dead. Topshop can claim that prized scalp.

The Topshop Unique fashion show was the first to be staged in the Tanks at the Tate Modern, the first to be live-streamed on the YouTube home page, the first to offer fashion-hungry consumers the chance to follow a "model's eye view" camera showing what a catwalk show looks like from Cara Delevingne's point of view. And customers who order pieces from the show now will receive them first – three months before they hit the shop floor.

None of this matters unless the clothes have good old-fashioned desirability. But there was plenty here to translate event-buzz into sales. Soft shearling coats in candyfloss pink and sensuous aubergine sequin eveningwear, kilt-pleated full skirts and punky PVC workwear pushed all this season's trend buttons.

Shepherd's pie with a Rolling Stone was the very British form of glamour served up by L'Wren Scott for her first London fashion week show. The American designer's boyfriend, Sir Mick Jagger, sat between Anna Wintour and Daphne Guinness as Scott introduced the British fashion industry to the concept of the shlunch: a show at which lunch is served. (Brunch? So last year.)

Scott's opulent show, on a catwalk running beneath the peerless chandeliers of Westminster's grand Institute of Civil Engineers, felt symbolic of the newly luxe and glossy tone for London fashion week. Inspired by the paintings of Gustav Klimt, Scott termed her dramatic, tactile collection "wearable decadence", a concept she developed into gold-leaf tattoos, and gowns embroidered in bugle beads coated in 23-carat gold.

Backstage after her Claridges catwalk show, the Mulberry designer, Emma Hill, said her elegant and vivid collection, inspired by the English countryside at night, had been about "going back to our roots, and at the same time going luxe. Next-level luxe." Example: the bag-of-the-season, always the touchstone of where Mulberry is at, is the Suffolk: a doctor's-style bag which harks back to the original Mulberry It bag, the Bayswater, but with added hardware and framing (for which read: a posher customer base, and a higher price tag).

The comedy touches that have helped give Mulberry a stratospheric profile in the blogosphere and on social media were toned down in favour of a confident emphasis on chic windowpane check wool coats and jackets and delicate leather capes and jackets.

Natalie Massenet, the new chair of the British Fashion Council, was thrilled with how the first London fashion week of her tenure had begun. "You can feel the impact and excitement already," she said. Massenet, who is working alongside the British Fashion Council's Caroline Rush, has ambitions for the UK fashion industry that extend far beyond this week's catwalks. "London fashion week is the showpiece of our industry, but there are other global brands that are based in London. We've got Mulberry and Burberry on the catwalk schedule – but we've also got Victoria Beckham, Stella McCartney and Jimmy Choo, who are generating jobs and income in London.

"We've reached a point now where we should have the confidence to celebrate those brands, wherever they show. Victoria Beckham was one of the most talked-about brands at New York fashion week – well, that's great for British fashion. Once upon a time there was a sense that if we brought Stella [McCartney] and [Alexander] McQueen back to London, we'd have done our job, but Caroline and I don't see it as that simplistic."

The epithets routinely appended to London fashion week are innovative and creative. To those, Massenet "would like to plug in global, strategic, businesslike, consumer-focused."

London fashion week "is not just an industry event any more", added Massenet. "Fashion is a consumer sport."

Within the city, closer ties are being forged "with the mayor's office, with retailers and with parallel industries such as film". Beyond that, Massenet's background as the head of internet shopping phenomenon Net-A-Porter.com ensures that the new regime is aware that "the internet has transformed the potential of what fashion week can be". So far, the London catwalk shows are livestreamed to 120 countries. This, noted Rush breezily, is "a good start".

London fashion week watches young British designer deliver an autumn/winter collection that fizzes with energy and ideas

This is what grace under pressure looks like. Last month Christopher Kane sold a 51% stake in his label to PPR, parent group of top-flight labels including Gucci, Stella McCartney and Alexander McQueen. François-Henri Pinault, chairman and CEO of PPR, described the Dalston-based company as having "tremendous intrinsic growth potential" and spoke of his "great ambitions for the brand", thought to include the first Christopher Kane boutique and a secondary, more accessible line within the next two years.

Kane's autumn collection, shown on the London fashion week catwalk on Monday, was a bigger event than ever before, with 55 models and a 900-strong audience.

The question was, would Kane's work – intense, instinctive, with ideas crammed into every margin – buckle under the pressure? Would his curve ball catwalk shows be replaced by box-ticking, commercial renditions of whatever trend the US department store buyers are currently relying on for sell-through?

Quite the opposite, as it turned out. The amplified scale seems to have energised Kane rather than stifling him, and there were enough ideas here for four or five collections. First came camouflage prints in misty blues, skirts trimmed with patent kilt buckles. Next came a series of burgundy and navy dresses, panels of velvet delicately strung together by braid.

This was followed by coats with silky feathers sprouting along the seams, so that the models looked like very slender teddy bears spilling their couture stuffing. It didn't all work – the outsize fox fur trims were a jarringly obvious "luxe" touch which sat oddly with the rest of the collection – but it was a feast for the eyes.

Kane, 30, is the first from his generation of London designers to make the leap from London fashion week star to big-time player. The evidence of this week so far is that PPR backed the right horse. Many of the hip names who hit the sweet spot in September have shown slightly flat, underwhelming collections this time around, as if the pressure of being taken seriously has induced catwalk stage fright.

In the final section, Kane spelled out the starting point of this collection, with screenprint renditions of a cross-section of a brain. Backstage after the show, he explained how he had been looking at MRI scans, "and how in a healthy brain, there are all these explosions going on".

Travelling in upstate New York, he found some pieces of lace which seemed to mimic the patterns; from there, the idea evolved into what he termed the "brain trim" fragments in the velvet dresses, and the feathered seams, which connected with projecting the inside on to the outside, and using sheer tulle edged with black velvet piping to echo x-ray images. "I didn't want to do, you know, the obvious," added Kane, rather unnecessarily.

Kane's longtime mentor Donatella Versace declared it his "best show ever" as she delivered a backstage hug. Salma Hayek, movie star – and more pertinently in this scenario, the wife of Pinault – pronounced it "amazing." Louise Wilson of Kane's alma mater, Central Saint Martins, praised the "grandiose gesture" of the sheer number of ideas. Still clutching a lint roller like a fashion week rosary, Tammy Kane, the designer's sister and close collaborator, denied that Kane had come up with more ideas in response to the added pressure. "To be honest, we could have done a show like this every season," she said. "It's just that we didn't have the opportunity until now."

While Kane sets out to prove he can cut it in the top flight, Burberry has set itself the opposite challenge. Designer Christopher Bailey believes Burberry can be both a global powerhouse brand and one with which consumers feel a warm, emotional connection. It is an ambitious balancing act. But Burberry – ahead of the curve in its commitment to digital engagement and utilising social media to form relationships with potential customers – is better placed than any other brand to pull it off.

This collection, entitled Trench Kissing, was a catwalk allegory of Bailey's devising. The trenchcoat-clad beauties played the role of Christine Keeler, while the provocative, rubber-and-leopard collection represented the naughty side of the establishment – which in this case is, of course, Burberry itself.

"I guess I wanted to say that even something very establishment and serious, like a big heritage brand, can have a sexy, subversive, romantic side," said Bailey after the show.

Keeler looked good in a trenchcoat; she also looked great naked. On the catwalk these two images were deliberately blurred: a trenchcoat in transparent coloured rubber was worn over heart-print knickers, while slinky leopard tailoring was accessorised with fetishistic gold-metal belts.

And should there be anyone watching at home who still does not feel the love – not only are the heart-print handbags available to order directly from the livestreaming of this show, but online customisation enables them to be delivered monogrammed with the customer's initials.

After Burberry's Kensington Gardens show, attention turned to Lancaster House in St James, where Tom Ford chose to hold his first official catwalk show since parting ways with Yves Saint Laurent in 2004. After his phenomenal success at Gucci, Ford walked away from the catwalk schedules nine years ago with a significant personal legacy and enormous personal wealth, two assets which allow him the freedom to engage with the fashion industry on his own terms. This season, that meant a catwalk show staged not on the bigger platforms of New York or Paris but within walking distance of his Mayfair base.

The show is a new and glamorous feather in the cap for the once humble LFW: Ford's red-carpet looks, for men and women, have established him as a fashion player in the Hollywood machine on a scale not achieved since the heyday of Giorgio Armani.

Sex infused Tom Ford's high-roller event, punk was a big influence at the likes of Preen and Christopher Kane and olive oil green will be one of the trends of next season, along with boyfriend-sized aviator jackets and loveheart motifs, writes Jess Cartner-Morley.

Once a launching pad for new designers, it is fast becoming the main event. But LFW mustn't let the luxury and money crush its sense of silliness.
Click here to see a gallery of the highlights from the week

On Monday evening, walking through St James's in the dark, looking for the Tom Ford show, I stopped to ask directions. "Over there, madam," a kindly security guard explained. "Do you see where that Bentley is pulling up, over by where the black velvet carpet starts? Right next to that row of rather handsome gentlemen in tuxedos? I should think that's what you're looking for, shouldn't you?"

Like, doh. How hard can it be to find a fashion show, right? But in my defence, London Fashion Week didn't used to look like this. It used to be more a case of: keep your eyes peeled for the gaggle of work-experience kids wearing cheap, uncomfortable high heels and outfits borrowed from the fashion cupboard, huddling together for warmth in a cheap marquee. Bentleys and tuxedos? Not so much.

The setbacks-and-comebacks narrative of London Fashion Week over the past decade makes for a great soap opera. To precis 50 trillion words in Womenswear Daily: we were on the ropes, almost consigned to a footnote in history. But we were plucky and made an out-of-the-box comeback. Then, just as we were getting close to our happy-ever-after, recession struck. However, instead of giving up, we came out fighting with collections that had everyone cheering the noble British underdog. And around 2012 we got really good.

So, did we get better this week? To be totally honest, no, of which more later. But we did get very, very posh. The Ford show was a high-roller event from beginning to end. There was a ratio of around one champagne waiter per guest, and the casting was a no-expense-spared roll call of rarely-seen-in-London beauties. But it wasn't just the money that had been lavished: this was an event that felt special, from the plentiful supply of fabrics that are usually bestown by fairy godmothers, to the perfection of Charlotte Tilbury's hair and makeup.

London, for so long the fashion nursery slopes where talented kids practise before hitting the big time, is fast becoming the main event. As well as Ford's show, there was L'Wren Scott's fashion-theatre-lunch concept the previous day: a sit-down Sunday dinner of shepherd's pie, served in front of a collection in which perfectly honed silhouettes were lovingly highlighted and celebrated with gold bugle beading, pink leather, purple tweed shot with gold thread, and 23-carat arm tattoos. And to complete the 360-degree fanciness of the event, one could just glimpse, between the floorlength gowns and the pale, supple leathers the sight, on the other side of the catwalk, of Mick Jagger helping Daphne Guinness take the lid off her individual bottle of ketchup. Which is surely about as posh as it gets.

"We've gone very luxe," was the first thing Mulberry designer Emma Hill said to me backstage after the label's Claridges show. The balloon-popping sense of silliness that has always defined British fashion was less in evidence this week. Sometimes it worked brilliantly: at Mulberry, the top-drawer fabrics used for coats and the gleaming new frame that rings the changes between the old Bayswater and the new Suffolk felt like a logical stepup for a brand that has outgrown its homely beginnings and is taken seriously all over the world.

But I do worry that some designers are jumping the shark with the whole seriousness thing. Now, maybe I read too much into this stuff, but I felt as if the in-vogue show venue of the week – a glassy office block, the kind with a view of the Shard and dizzyingly fast lift – was indicative of a certain mindset. A kind of Oh-God-everyone's-looking-at-us-we've-got-to-be-serious designer's mindset, brought on by the new level of respect in which British fashion is held. This brings with it some unwanted baggage, in the shape of a drab cleverness that is neither exciting nor commercial.

When I spoke with BFC chairman Natalie Massenet last week, one of the designers she singled out for praise was handbag mogul Anya Hindmarch, whom, she said, "has set a new standard for thinking creatively about fashion week and finding the most innovative ways to exhibit product". On Tuesday morning, Hindmarch excelled herself with her best piece of handbag-theatre yet: 50,000 dominoes set up as a giant train set, which fell to reveal this season's Anya Hindmarch handbags concealedbehind them. It was extravagant and ambitious and must have cost a fortune – but it was also smartly ontrend (shades of Vuitton's £18,000 checkerboard dress) and brilliantly, laugh-out-loud silly. This is what London fashion should be about. We may be on the high-roller table, but we can still have fun.

We are in dire need of style guidance in the wearing of black tights. Jess Cartner-Morley is here to help

'Scan any fashion page and you'll see winter clothes styled, more often than not, with bare legs'

It is a truth universally acknowledged that a woman wearing a skirt or dress at this time of year will need to wear tights. Except, it's not. It's a truth universally acknowledged everywhere except in glossy magazines, on red carpets and in newspaper fashion pages. (Also, in certain towns in the north of England, but that's a whole other issue.)

There is a fundamental disconnect between fashion and the real world when it comes to hosiery. Walk down any urban street in winter, and you will see a forest of black-opaqued legs. But scan any fashion page and you'll see winter clothes styled, more often than not, with bare legs. The shoot might be on location in the Highlands in a rowing boat on an icy lake, the coat might be fur-trimmed and the dress cashmere – but the legs, more often than not, will be bare. Mea culpa: even on a page such as this, which is all about how us norms grapple with fashionable clothes, I often end up being photographed in bare legs when roadtesting winter looks. Bare legs are fashion's shiny prefect badge (see also: shoulder robing your jacket; using a clutch in daylight).

As a result, we are in dire need of style guidance in the wearing of black tights. There is a woeful paucity of role models in the important skill of teaming a 60-denier opaque with an interesting outfit. So, when we wear a coloured skirt with black tights, we go for the easy option of a black or neutral top. But it doesn't need to be like that. A simple way to make black tights work is with strong colours: if you team muted pastels with a matt-black leg, it kills the subtlety, but add gleaming jet-black to a jewel-like mix of emerald, sapphire, fuchsia, ruby, well, then it is right at home.

The same goes for what you wear over your outfit. That black cardigan you always wear? On the fashion food chain, it is scarcely a notch above your dressing gown, and you don't wear that out of the house. Sorry to be blunt, but it needed saying. A black cardi will make coloured clothes and black tights look dull, so try a navy or charcoal blazer instead.

Go on, try it. It's time for fashion to reclaim the black opaque. And as you can see, I'm in.

• Jess wears silk shirt, £225, by Equipment, from Selfridges.com. Skirt, £630, by Sophia Kah. Cashmere and silk tights, £115, by Wolford. Stack heel sandals, £24.99, by H&M.

Styling: Lucy Trott at Carol Hayes Management. Hair and makeup by Dani Richardson using Sisley Cosmetics.

Jennifer Lawrence triumphed in Dior, while Anne Hathaway's satin dress turned treacherous and Amy Adams was swamped by her ruffles. When it comes to the gents, check out Eddie Redmayne's bohemian velvet and Ben Affleck's dress-for-success three-piece suit

This was Jennifer Lawrence's night. She won the Oscar, and she won the red carpet too, in Christian Dior. The formula for a successful Oscar dress is similar to that for a successful Oscar film: you want plenty of drama but not too many complications. This dress does that perfectly. The silhouette is knockout, and there are no fussy styling details to detracting from that. The swept-back hair, neat silver clutch and delicate jewellery are all in harmony. There will be celebrations at Christian Dior HQ in Paris: the awesome internal structure (note how it looks good from every angle), the perfect skin-flattering pale (moonshine?) and the dappled texture to the fabric (so it never looks shiny or crinkly, even under a million flashbulbs) are a great advertisement for the Dior atelier.

I think we can assume it wasn't Anne Hathaway's goal to be upstaged by her own nipples, but that's what happened in this Prada gown. The dress was a last-minute choice: LA "sources" say she switched from her usual Valentino at the last minute. Those aren't actually her nipples, by the way, they are darted seams in the fabric. (Look at how the skirt of the gown holds its shape as it falls to the floor, and you can tell that the satin is much too heavy for nipples to bore through like that.) But such dressmaking niceties won't help save this dress for being remembered for the nipples. I don't love this look anyway: too angular and sharp. She looks like an enormous, shiny pair of scissors.

Amy Adams wore Oscar de la Renta. I think this dress could have worked in black – picture it, a sort of black-swan red-carpet glide – but it doesn't work in grey. It doesn't even make sense in grey. Who wears a grand, beaded-bodice, ruffle-tier skirt ballgown in the colour of dishwater and rainclouds? I guess she was going for sophisticated, but it comes off like fashion self-sabotage, which is insane, because the shape is fabulous. Like I said: shoulda gone for black. Also, there's too much going on in the bottom half of the dress, to the point where it completely upstages her face.

Girlfriend looks HOT in this dress, right? I so much prefer the later-years Reece Witherspoon – the older-and-wiser, second-husband, curvier and all-round saltier version – to the cookie-cutter American poppet we first met. This Louis Vuitton dress feels like the first confident rendition of that persona on the red carpet. (Reese's 13-year-old daughter helped her pick it out, apparently, which is cute.) The colour is bold, not standard red-carpet fare, but works brilliantly with her hair, and the trompe l'oeil waist-cinching shape is a fashion detail that will make sure this look gets plenty of fashion-page action.

Jessica Chastain's Armani Privé dress is elegant and timeless, a bona fide movie-star gown, with bona fide Harry Winston jewels. When I first saw her, I thought I preferred last year's fabulous Alexander McQueen black-and-gold number – at first glance this looks like it could be the petticoat to that dress. But the subtlety is growing on me: the colour is the perfect compliment for that incredible hair of hers and those awesome red lips, and I love how the swirling seams of beads make this fitted shape look softer than it is.

Eddie Redmayne went traditional for Oscar night. He often rocks a wolfish bit of Burberry velvet on the red carpet, but went for a straight-up tuxedo, by Alexander McQueen, complete with satin lapels, bow tie, and studded shirt buttons. The skinny cut of the suit keeps it modern, but the piece de resistance? Those velvet slippers, which show the Afflecks of this world that having a beard isn't the only way to tell the world you have a bohemian/subversive side.

My feeling about Kerry Washington is that she loves her fashion probably a little bit too much to really nail it on the red carpet. She's being held back by choosing the gorgeous party dress over the grandstanding Oscar Dress. This is by Miu Miu, and if she hit up the dancefloors I bet she was the belle of the ball, but the two-tone effect doesn't quite work on the red carpet: she looks as if she's wearing separates, and the impact is muted.

Sally Field in Valentino is one of my favourite looks of the night. The colour – bold Valentino red – never fails to deliver. The sheer long sleeves are a graceful way to draw a veil over arms – no point competing with Jennifer Aniston on this, you gotta pick your battles – without looking prematurely grandmotherly. I love the classic pear-drop earrings, and the simplicity of no baubles cluttering up that clean neckline.

Jennifer Aniston knows her brand. She has never gone in all-guns-blazing on the red-carpet wars, preferring to opt for the dress that is straightforwardly pretty and the safe, familiar choice over the straight-off-the-catwalk attention-grabbing numbers. That's who we we want Aniston to be – the unthreatening, smiley girl-next-door. She's made a fine career out of this, and she's not about to jeopardise anything by going off-brand in some crazy dress. So, she wears strapless Valentino satin, has a great blow-dry, and smiles a lot. Job done.

There is something weird going on with Ben Affleck's bow-tie, which needs straightening. But that aside, he scrubbed up well. The three-piece tuxedo and polished shoes say to the academy: now that you're taking me seriously, I don't have to play the maverick/rebel any more. His wife Jennifer Garner wore Gucci, and $2.5m worth of diamonds, so perhaps he was blinded by looking at her and forgot to straighten the tie.

George Clooney and Stacy Keibler are unusually understated here. Clooney has taken on Daniel Day-Lewis's Lincoln beard, which is a little out of his silver-fox comfort zone. Keibler, meanwhile, is doing her own version of the silver fox look, in a retro-style beaded Naeem Khan dress. It's classy, rather than sexy.

Helena Bonham Carter is singlehandedly keeping this neckline alive. It's the neckline posh girls wore to balls in the 1980s and 1990s. A sort of low-scoop with plenty of cleavage but everything squished down safely, all the better for pogo-ing in when a bit squiffy. Literally nobody wears this neckline any more, ever, even posh girls at dreadful parties, except for Bonham Carter. But does she care? Look at that face. She couldn't care less. She's off to get squiffy and pogo. She's awesome.

Amanda Seyfried is in Alexander McQueen. I don't know who wrote the memo to the red-haired women telling them grey was a flattering colour (see also: Amy Adams) but I don't think she'll be super-popular right now. The dress is exquisite and the neckline is delicate and beautiful but the shade is oddly underpowered. You can tell she's trying to vamp it up with the pose, but it's not quite working.

Hey, Catherine! Beyoncé called, and she wants her gold dress back. Michael Douglas and Catherine Zeta-Jones took a break from playing golf to hit up the red carpet. I love how the dynamic never changes with these two: he is still the slightly rogueish elder statesman, and she is the showgirl in swooshy metallics.

Nicole Kidman is good value on a red carpet as her dress choices tend to be either brilliant or brilliantly awful. This is one of the good years. She gets props for wearing a gown straight off the catwalk – this is look number 27 from the London fashion week show by L'Wren Scott, the designer girlfriend of Mick Jagger, which took place just seven days ago. Obscure red-carpet fact of the day: this dress is inspired by the paintings of Gustav Klimt.

The question raised by this photograph of Christoph Waltz and Bradley Cooper is, what does the waistcoat mean? Personally I think it's a symptom of the Downton Abbey effect, because we all know how the Americans love that show. Bradley Cooper wore a tuxedo by Tom Ford, custom-made from recycled fabric as part of the Green Carpet ethical initiative.

There isn't a dress in the world that could make Kristen Stewart look like anything other than Kristen Stewart. She's in Reem Acra, and it's feminine and refined, but she's on crutches, and her hair looks insane, and you get the feeling there was either a tantrum earlier or there will be one soon. She's K-Stew, that's how she rolls.

Salma Hayek's husband owns Gucci, McQueen, Stella McCartney and Yves Saint Laurent, which must come in super-handy on nights like this. She basically married the world's best wardrobe, although obviously I'm sure she totes loves him for his personality. This dress is by McQueen, and she looks incredible, like an Ancient Egyptian goddess.

Helen Hunt's dress is this Oscar's big ethical-fashion moment: it is by the Conscious collection for H&M. Which is fantastic. However, just because you're saving the world, doesn't mean you should skip ironing your clothes.

The Day-Lewises were this year's Oscar couple. He won his third Oscar. She is probably the most beautiful woman at this ceremony. He wore navy Domenico Vacca, which totally works, and everyone breathed a sigh of relief he didn't show up with a stupid beard. And she showed why black lace Dolce will never, ever let you down.

Stop dreaming about summer, and start celebrating spring ... with a new jacket

Designer appointed to bring broader appeal to revered label takes 'semi-fitted' silhouette as touchstone

Balenciaga is the single most rarified name on the Paris fashion week schedule. Cristobal Balenciaga, who died in 1972, was the fashion designer's designer, the man of whom Christian Dior said: "He is the maestro, the rest of us just musicians." The names of Chanel and Dior may pack more punch in modern popular culture, but the cognoscenti revere the legacy of Balenciaga above all others.

The recent appointment of Alexander Wang as the house's new designer was therefore something of an eyebrow-raiser. How can a 29-year-old designer whose clothes are rooted in the Californian beach culture of his teens and the downtown New York slouch-chic of his student years make sense of Balenciaga, which for the past 15 years has been steered by the very French, very intense Nicolas Ghesquiere?

Wang's debut suggested that the commercial instincts which led PPR, the luxury brand group behind Balenciaga, to hire him were shrewd. Francois-Henri Pinault of PPR has said he hopes Wang's Balenciaga will be "approachable", which is an only slightly coded way of saying he hopes it will sell. There is frustration within PPR that the reverence in which Balenciaga is held within the fashion world does not translate into brand visibility on a wider scale. The Lariat bag was the one barnstorming commercial success by Ghesquiere, who otherwise continued in the grand Balenciaga tradition of making exquisite clothes aimed rather narrowly at a fashion elite.

The stardust in Wang's own-label collections at New York fashion week has always been a sixth sense about what young women want to wear, and it is that connection which PPR hope he can bring to Balenciaga. Backstage, Wang referred to the show as "the first chapter" in a mission to retell the story of Balenciaga so that it strikes a chord with a broader audience. Where Ghesquiere's design processes were intricate and multi-layered, Wang's approach was to present the subtle, nuanced codes of Balenciaga in a new, simple way. As Wang commented after the show, Balenciaga himself "took the avant-garde, and made it everyday".

This was a confident, uncomplicated debut. For chapter one, Wang took as his touchstone the "semi-fitted" silhouette which was Balenciaga's response to the hourglass New Look with which Christian Dior seduced the postwar fashion world. Semi-fitted jackets accentuate the waist at the front, but are puffed with volume at the back, a shape which Wang infused with a new sportiness. The rounded shoulders which are a Balenciaga signature were given a playful teddy-bear fur finish. In the draping of a cutaway evening dress there was a nod to the loose fit of the racer-back vests which are a signature of Wang's own label collection – but here on the Avenue George V, a gleaming sculpted bodice was glimpsed beneath. While the silhouette made reference to Balenciaga's mid-century rivalry with Dior, the slick, minimal take on couture suggested that the aesthetic of Wang's Balenciaga might run alongside, rather than diametrically opposed to, that of Christian Dior under its current designer, Raf Simons.

The debut was imbued with cool precision. The venue was the historic headquarters of Balenciaga on the Avenue George V, where a suite of elegant first floor rooms were made over in stark monochrome: whitewashed walls, doorframes picked out in black paint, the parquet a deep black walnut. Window boxes were filled with black-sprayed box hedge, out of which grew slim budded branches rising to the top of the glass to make the prettiest of blackout blinds and protect the carefully calibrated lighting from rogue sunbeams. The slim silver benches padded with black velvet snaked maze-like around endless corners, so that the audience were given a view of each outfit from different angles as the models turned: crucial at a house where silhouette has always ruled over decoration.

The message that shape is key was underlined at every stage, even in the decorative motifs themselves, by the theme of marble. The invitations were backed with an image of white-veined black marble, while the catwalk was a reverse image of black-on-white. Marbled green and black fur and a stunning intarsia knit which mimicked a cracked, marbled finish featured, as did sections of marbled lining exposed in a simple, chic touch where the edges of a neckline were pinned back.

This collection will be judged by Wang's new bosses not by how well-received it is by those who attended Thursday's show, but by whether it can reach a new audience. Pinault recently told CBS that Wang "is young and has a very universal culture. He is American with Chinese roots. His family are based in Shanghai." Wang, who speaks Mandarin, has a high profile in China where his own-label already has a Beijing flagship. There seems little doubt this is part of his appeal to PPR. Balenciaga has recently stepped up its Asian presence, with new openings taking the total number of stores in mainland China to 11. Isabelle Guichot, Balenciaga's CEO, said recently: "We have huge ambitions, and we have huge reserves of growth."

A sumptous exhibition in Paris showcases beautiful gowns made over the past century, many of them embellished with Swarovski crystals – and it won't cost you a centime to visit

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In Paris, for the next four months, you can get haute couture for free.

Well, almost. An exhibition at the Hotel de Ville, opening on 2 March, brings together 100 dresses from the 118-year history of haute couture – and there is no entry fee. The frocks include prize pieces from Worth, Coco Chanel, Paul Poiret, Christian Dior and Madame Gres, as well as contemporary looks by Alexander McQueen, John Galliano and Riccardo Tisci.

It's a lively and thought-provoking selection, with gowns made a century apart juxtaposed to draw out common themes – as you'd expect, since the curator is Olivier Saillard, newly appointed director of the Musee Galliera (the Paris equivalent of the V&A fashion galleries) whose recent work includes The Impossible Wardrobe, a 40-minute one-woman fashion-show-meets-avant-garde-theatre-piece, starring Tilda Swinton.

The exhibition is made possible by the support of Swarovski, whose crystals embellish many (although not all) of the dresses, and Nadja Swarovski was in attendance at Thursday's opening. "I grew up listening to my grandfather tell stories about driving two days to get to Paris, to see Coco Chanel about a dress," said Nadja. "Or about how Christian Dior wanted a stone that represented the Northern Lights, and that was how that particular crystal came into being." She hopes this show will celebrate the longstanding relationship between haute couture and Swarovski, one which lapsed in the 1970s – "crystal figurines", she says crisply, with a roll of her eyes – but was reignited when, through Isabella Blow, the company made contact with Alexander McQueen and Philip Treacy, and "the fashion industry remembered Swarovski". Pushed to pick a favourite out of this century of dresses, Swarovski plumps for an elegant white halterneck gown made by Christian Dior for the Duchess of Windsor.

The message of the exhibition, Saillard says, is twofold. "That there is something precious about haute couture – but also that it is part of our world, our culture." The free admission is, he says, a terrific symbol of that. "Haute couture is special," says Saillard. "In ready-to-wear, designers must always be trying to predict the future. But in haute couture, it can be more relaxed, and more about the present."

The looks are presented in pairs or trios, to tease out similarities. So a rich green Worth gown from 1895 is placed beside a Christian Lacroix catwalk look from 1991 that uses the same devore technique. A burnt orange, funnel-neck evening coat by John Galliano for Dior (1998) stands next to a Paul Poiret version – same silhouette, same shade, similar embroidery – from seven decades earlier. A navy mousseline Coco Chanel shift from 1923 is presented alongside a navy mousseline shift dress from Bouchra Jarrar's current collection.

Swarovski is a generous benefactor of the fashion industry. Nadja Swarovski readily admits that this is intended "to position ourselves as a fashion authority," but insists also that the family is keen to support an industry that, through good fortune, has helped to make the Swarovski fortune. Daniel Swarovski moved the Swarovski headquarters from deep in Austria to Bohemia, in order to be close to road and rail links to Paris. As a result, when the iron curtain fell, Swarovski was the only Austrian crystal company able to work with Paris and with Hollywood, gifting it a virtual monopoly.

'A winter coat can be a diva, but a spring jacket needs to be a team player. This is not the moment to experiment'

You know that saying, "Ne'er cast a clout till May be out"? I love that. I love that we have a proverb about vests. Proverbs about vests are the sort of thing that makes this country great. And it is excellent advice. You can't trust the weather at this time of year.

Rather than be grumpy about this, I suggest we look on the bright side. Instead of waiting for summer to arrive, and ripping out photos of sandals and sundresses, we should celebrate spring. After all, we don't necessarily get a summer, but spring turns up every year without fail.

A spring wardrobe starts with a jacket, of course. The key elements here are versatility and fit. A winter coat can be a diva, but a spring jacket needs to be a team player. This is not the moment to experiment with a peplum if the rest of your wardrobe is straight-up-and-down, or the right time to indulge a yen for neon florals if everything else you own is navy. Instead, look for a jacket that complements and pulls together whatever your default look is. If you're all about trousers and shirts, find a blazer; if you're usually found in jeans and something pretty in cashmere, a fluffy or furry gilet might work best.

Pick a jacket that is a note or two sharper, on the scale from casual to formal, than most of your clothes. Jackets work better when they are ratcheting up the style level than when they are bringing it down a notch. Consider: a tuxedo jacket over jeans and a T-shirt is a classic, but a denim jacket over a cocktail dress really isn't (unless you are Nigella Lawson).

As for fit, pay attention to how much room for manoeuvre there is underneath, because you'll want to be wearing this over a varying number of layers, depending on the weather. But avoid oversized: the best spring jackets can work with a rainproof layer over the top, so your bejacketed silhouette needs to remain relatively sleek. If you're wearing a blazer, you can add a light trench; if you're in a baseball jacket over sportswear, you could sling on a hooded parka. You are prepared for all scenarios. And no, you won't be cold without your proper coat. Not so long as you were concentrating on the bit about vests.

• Jess wears blazer, £100, shirt, £20, tailored dungarees, £100, and sandals, £55, all topshop.com.
Styling: Lucy Trott at Carol Hayes Management. Makeup: Dani Richardson using Sisley Cosmetics.

Dior's latest collection is bursting with a rich variety of allusions to art and fashion history

Just five days after the blockbusting triumph of dressing Oscar winner Jennifer Lawrence for the red carpet, the house of Christian Dior on Friday scored an arthouse hit at Paris fashion week.

Lawrence's showstopping Hollywood gown – widely acclaimed by fashion critics, despite being so enormous as to cause her to fall over in front of an audience of millions – scored maximum points for the Dior brand for a mass audience. In Paris, designer Raf Simons aimed to impress in a very different key, with a second ready-to-wear collection bursting at its perfectly finished seams with meaningful references to art and fashion history.

The central reference was Andy Warhol. Simons filled the catwalk with silver balloons, giant versions of those Warhol used to decorate the Factory. Warhol's early drawings of faces, butterflies and shoes were printed on handbags and embroidered on to silk evening gowns.

Warhol is an ingeniously clever allusion for Simons to alight upon. Of all the Parisian houses, Dior is associated with the most traditional, conservative aesthetic. The perennial appeal of the New Look is a double-edged sword for Simons, giving the label eternal prestige but tethering it to the 1950s, a decade that is a byword for respectability. Who better than Warhol to make the point that the 1950s could also be forward-looking and subversive? The illustrations used in the collection were all drawn in Warhol's early years, which cross over with Christian Dior's Paris heyday. This message was pointedly reinforced by the shownotes, which specified the dates of each: "shoe 1955", "female head 1956-1958".

In a gallery-like marquee next to the Hotel d'Invalides, the Warhol balloons were suspended over a catwalk painted with fluffy white clouds on a blue background. It was a reference to the surrealism of Magritte, who used blue skies in incongruous settings (interior walls, night-time scenes) but also a link to Simons' previous collection: in the advertising campaign now running for Dior's current collection, models perch on window ledges through which the same Magritte sky can be glimpsed. This collection, then, matches the one seen through the window of the last one: the narrative of Dior's post-Galliano story is being plotted as carefully as a thriller.

The message was received, loud and clear. But some of the most desirable pieces in this collection were those which stood independent of the arthouse theme. A collarless grey astrakhan coat, tailored above the hip before fluting into a swinging skirt, was simple and perfect. The bar jacket trouser suits, with the modernised peplum of the bar jacket atop perfect Oxford bags, were utterly modern and desirable. The dominance of crisp, collarless cuts and graphic lines showed the remarkable degree to which Simons has quietly stamped his personality on Dior.

This was a cerebral collection, but if Simons can paint a Dior picture both in these nuanced tones and the flashier palette demanded by the red carpet, he will flourish. Figures released this month suggest he has already had a positive impact on Dior's bottom line: sales rose by 24% in 2012, following Simons' appointment early that year.

Roland Mouret, son of a Lourdes butcher, has established his home in the Suffolk countryside and his business headquarters in Mayfair. A more Anglophile lifestyle it is hard to imagine, but for the past six years he has staged his catwalk shows in Paris. And you can tell.

This the designer himself acknowledged, while checking the final looks on models backstage before his show on the Rue Castiglione. "Every season I show here, the aesthetic becomes more and more Parisienne. The trends which happen in London or New York matter less here than the codes of Paris style, which are unavoidable – irresistible, in fact." Asked to divulge a few of these codes, he listed red with black, leopard print, strong shoulders, and sheer tights the French call fumé. ("As if cigarette smoke is wrapping around your legs," Mouret explained to confused Brits.)

The ultimate reference, he said, is Catherine Deneuve. ("She's blonde, but she's a bit nasty.") The models wore their hair in sprayed and polished chignons, their eyes obscured with shades or by dark shadow. There was a musky hint of the strong, classic chic of 1980s Yves Saint Laurent in both the clothes and the styling.

The beating heart of this label will always be an evolution from the Galaxy dress which first shot Mouret to fame. Fitted dresses with full-length back zips, prim but sexy, revealing little flesh but amplifying every curve were as instinctively desirable in this collection as they have ever been, panelled in tints of leopard print, or combinations of black, ivory, crimson and tobacco. (Mouret aficionados will be interested to learn that the width of the zipper has been increased this season, for strength, from 4mm to 6mm.)

As is often the case for Mouret, the dresses seemed to suck in all the oxygen, leaving trousers, blouses and jackets looking weak by comparison. But Mouret may have hit upon an important new strength with handbags, launched for the first time this season. Discreet, structured, with subtly gleaming hardware and an air of quiet confidence, the bags compliment the signature dresses, and are strong enough to steal their limelight. They carry echoes of Hermès, most classically Parisian of all handbag labels, and have names to match: the day bag is named Hugo, after Mouret's favourite writer, while the evening bags are Le Sept and Paris Paris, after the nightclubs of his youth.

Even by the fashion house's high standards, this softer and more approachable collection has the makings of an instant success

Backstage after a hit Paris fashion week catwalk show Phoebe Philo, the British designer of Céline, was asked how she felt about her designs being the most copied in the fashion industry, echoed everywhere from lesser catwalks in New York and Milan to the market stalls of London and Shanghai.

She smiled, shrugged, and pronounced it "flattering. I do notice, of course I do; I see it in the street." Is she ever tempted to buy the endless high street versions of her signature minimal chic? "I don't have time to go shopping, otherwise I totally would," she said.

It was the perfect Céline answer. Cool and laid-back where others would be shrill and overblown; classy without being snobbish; quietly resonant of the fundamental issues of modern life (time, the lack of); reinforcing an image of a woman who loves clothes but maintains a sense of proportion. These, even more than the round-shouldered coats and the funnel-neck sweaters, are the codes Philo has written for Céline during her six years in charge.

After taking an obtuse turn with her collection last season, which included flat walking sandals lined with brightly coloured teddy bear fur – soon to go on sale for £840 a pair – this collection had the makings of an instant hit. The mood as the show ended was a feeling that even by Céline standards, this was particularly strong.

"Intimacy, softness, instinct and desire" were Philo's words. The shape and colours were feminine, with skirts in nubbly cream or peach wool cut in a close curve over the hips before fluting to below the knee. The Céline woman can at times seem cool to the point of guardedness, but she seemed softer, more approachable this season. Handbags were made from the same fabrics as the clothes, and hugged the body, so although styled for the outdoors the models looked cosy rather than armoured.

Oblique references and unnerving touches are part of any Céline show. On each seat was a scrapbook of visual references, including a detail from Van Eyck's 1434 painting, the Arnolfini Marriage; photographs of cloud formations; and an image of NUD 3, Sarah Lucas's abstract nude sculpture made from breezeblock and tights. On the catwalk were nuggets, curveballs and in-jokes. The idea of softness was elaborated into fur dresses, and coats which featured trompe l'oeil sleeves tied around the shoulder; there was a wink to fashion's vogue for checks with clothes in the checked weave of plasticised laundry holdalls.

It may be significant in terms of where the winds of fashion blow next that there was some synergy between this show and that of Miuccia Prada, who like Philo is a designer who goes her own way on what seems like an emotional hunch. (If there is a more strategic plan behind their fads and foibles, neither are telling.) Elements in this Céline collection – the naive cut of the coat collars, the just-below-the-knee-length skirts, the soft shell pinks – chimed with Prada, in a way that may indicate romance, intimacy and femininity, and may come to be repeated around the echo chambers of fashion.

Like Philo, Clare Waight Keller of Chloé is a Briton at the helm of a French label. Chloé is so fundamentally Parisienne that it is tricky territory for a British designer to inhabit while maintaining her identity, but Waight Keller is managing the balancing act. Her fourth collection blended Parisian polish (plenty of navy, touches of flirty sheer net) with London punch: the pinafore shapes and high-heeled loafers were an Alexa Chung-ish touch, while the designer credited "night buses, bike sheds, bare legs and cold nights" among her inspirations for the season.

British designer walks the line between feminine and masculine, and cracks the eveningwear conundrum with smart tailoring

Stella McCartney is the type of person to get straight to the point.

The power play between masculine and feminine codes in fashion, territory the British designer has always prowled, has been a recurring theme of this fashion season. So at her Paris Opera house catwalk show, McCartney cut to the chase.

The first outfit was a double-breasted pinstripe suit, the traditional uniform of the gentleman's club and of the most male-dominated workplaces. But into the skirt was inserted an extra circular swirl of fabric which gave a soft, swaying movement as it moved; double-sided stretch material hugged the waist to give the jacket a curving silhouette.

"I didn't just want to take feminine elements and stick them on to a masculine silhouette," McCartney said backstage after the show, "Because that's not how it works. I believe all women have a masculine side to their personality, but that it comes from within them. It's about inner strength, not about surface. So I wanted the flicks and kicks that represent femininity to come from within the pinstripe, rather than be an afterthought.

"A collection is always about an emotion, rather than a look."

"Feistiness?", suggested one reporter. McCartney, precise in all things, shook her head. "No, it's not feisty exactly. That's too aggressive. It's more about an inner strength that runs beneath femininity."

One of the designer's first internships was at Christian Lacroix, the most lavishly flounced and ribboned of Parisian houses, another was with a Savile Row tailor, and both aesthetics run through her label.

Notwithstanding some Stella classics – the grey wool sweater dress, this season with black lace inserts; the coloured coat, this season in deep violet – the centre of gravity of this label continues to shift towards eveningwear. The label has a growing presence on the red carpet, and the modern approach that has won McCartney celebrity fans is bringing in paying customers also.

The designer recently noted that eveningwear can be tricky as much of it tends to be either prematurely ageing, or inappropriately over-youthful. Having identified a gap in the market for eveningwear which is neither deadly sober nor absurdly whimsical, she is making clothes to fill it.

And eveningwear was a highlight of this show, with softly gathered silk dresses in the strapless silhouette enjoying a renaissance led by Raf Simons at Dior, and smartly tailored cocktail pieces with lapel detailing borrowed from the traditions of men's tailoring.

The designer's second collection for the house was full of bold energy and youthful iconoclasm - but almost no handbags

Hedi Slimane has not forgotten how to shock the fashion world, after all. His debut collection last October as the designer of Saint Laurent failed to deliver the visceral, game-changing act of rebellion which the industry expected from this most mythic of contemporary fashion designers. Instead, his first Saint Laurent catwalk show was a something of a damp squib: a paean to the 1970s haute-groupie which was nostalgic and familiar, rather than agenda-setting or challenging.

On Monday night, Slimane delivered the punch that was expected of him – albeit a fashionable six months late.

Catherine Deneuve, iconic muse of Yves Saint Laurent, took pride of place on the front row; but on the catwalk, the muse was Courtney Love. The formula for almost every outfit in the show consisted of: very short dress, worn with oversized cover-up (tartan shirt, leather jacket, duffel coat) and fishnet tights over pale skinny legs. The models wore little makeup other than thick, artlessly applied black kohl. Upon reaching the end of the catwalk each scowled at the photographers and wheeled around on their flat boots without posing.

Yves Saint Laurent himself was a rebel within the fashion industry. For Slimane to alight upon an era in which YSL has no particular relevance is, therefore, perhaps in keeping with the spirit of the house. There was a bold energy and a youthful iconoclasm to this collection. These elements are essential for keeping the Saint Laurent spirit alight.

And yet the disconnect with the Saint Laurent customer seemed at times alarmingly wide. In California, where Slimane lives and to where he has moved the design studio, nineties grunge is a deeply felt part of everyday folklore; but in Paris, it is an abstract concept. And the grunge roleplay did not provide much in the way of roles for accessories. There were almost no handbags in this collection – this girl, with her unwashed hair and kohled eyes and fishnets, has no yen for an expensive handbag. Yet the YSL woman, surely, loves her handbag. This was a second act by Slimane which leaves the stage intriguingly poised for the next.