Curious about a post she saw on Facebook, one weekend Cowdery dropped into the Leeds Community Clothes Exchange, a local swap shop. Four years on, she is one of its threedirectors, helping to oversee the 2,000 items – “designer stuff, vintage stuff, handmade things, wedding dresses” – that pass through the doors of the Woodhouse community centre each month.

Cowdery and I meet in one of those lunch hours that used to be spent shopping. Her skirt, top and cardigan are all from the Clothes Exchange; her boots are from the Autism Plus shop in Goole. “At the exchange, it’s one for one on everything,” she explains. There are no value judgments. A garment is saleable if all its buttons are present and there are no stains. Some prom dresses return again and again. “People take them, wear them, bring them back.” Regulars set aside pieces for each other. The fitting room is a place of encouragement.

As her involvement in the clothes exchange grew, Cowdery’s visits to Peacocks dwindled. Now, its shop floor struck her as “an explosion in a jumble sale”. She began to delete unopened emails from Asos and Topshop. She swore off buying new clothes for a year. “I thought I’d reach the end and think: ‘I’ve done that. I’ll move on,’” she says. Instead, “It changed how I thought about clothes."

Cowdery still loves clothes – especially anything velvet – but she has found a safe way to consume them. The clothes exchange enables her to refresh her wardrobe without adding to it. She can be acquisitive, as long as she relinquishes in equal measure. Where she once bought three pieces a month, she now swaps 10 to 15 – mostly things she picked up at the previous exchange.

Clothes come and go at the Basingstoke home of Sarah Fewell, too. In fact, so many parcels come and go that she knows her postman by his first name (Jay). Fewell has always loved cutting up old clothes, sticking on studs, even at 14 when most of her friends were into Hollister. But now she has turned her passion for preloved clothes into a sustainable version of fast fashion.

Fewell runs a shop called Identity Party on the website Depop, which since being established in 2011 has offered its 10 million users a blend of eBay-style trading with Instagram-style posting. Her brand is “a lot of 80s, 90s, quite bohemian, grungy”. She especially loves “selling things with animals on, a good old ugly jumper and anything by St Michael.”

Two years ago, in the second year of a politics degree at Goldsmiths, University of London, Fewell was browsing the charity shops when she saw “a really nice dress that wasn’t for me”. She already had a Depop profile, having sold some unwanted clothes, so she bought the dress, listed it as “‘very Phoebe from Friends” and it promptly sold.

She bought and sold relentlessly during her third year. “When I left university, I thought, I don’t want a real job.”