'This year's jeans-and-jumper combination doesn't look like a fashion statement at all. It just looks like what today looks like. That's how you know you've got it right'
I know what you're thinking. I look as though I'm having a day off. I'm wearing jeans and a jumper, for goodness' sake. That's not fashion. That's just clothes. Where are the bells and whistles?
Oh, my dears, will you never learn? There is no such thing as a day off from fashion. Fashion never stops. It's not just cover girls in cocktail dresses who channel fashion. We all do it, every day, even when we're in jeans and jumpers.
Especially, in fact, when we're in jeans and jumpers. This is the most interesting aspect of fashion, because it's the bit we all take part in. Those people who diligently buy into the vogue for electric blue or the craze for optical prints: they are not exactly a representative cross-section of the population. They're – how to put this delicately? – different. They are fun to look at, but you can't draw too many conclusions from the behaviour of people who willingly wear dungarees, because they are clearly irrational. The off-duty jeans-and-jumper outfit gives away more about your life as it really is.
In half a decade, jeans can go from skintight to falling down, from faded and ripped to a rich indigo gleam. Hemlines go from floor-length to rolled up; waistlines from above the belly button to below your knicker elastic. Woollies flip from chic cashmere (the good times when we have money to burn) to intarsia reindeers (the bad times, when we are seized by nostalgia for childhood and the Way Things Were). A vogue for postage stamp-sized sweaters that end neatly at the waist can be replaced, within a year, by a trend for outsized cardigans.
This year's jeans-and-jumper combination is a coated jean – a waxy finish halfway between denim and leather – worn with a textured jumper. Where this time last year was all about the jolly Christmas jumper, the naive Scandi detective knit or the waffle-stamped textured knit, this year's sweaters are less attention-grabbing. They are the quiet foil to the rock'n'roll coated jean. You look in the mirror and you think: this doesn't look like a fashion statement at all. It just looks like what today looks like. That's how you know you've got it right.
• Jess wears jumper, £110, Reiss. Jeans, £265, by Citizens of Humanity from net-a-porter.com. Shoes, £49.99, by Zara.
Photograph: David Newby for the Guardian. Styling: Melanie Wilkinson. Hair and makeup: Dani Richardson at danirichardson.co.uk using Mac Cosmetics.