Twice a year, the international fashion collections reveal new lengths, shapes and colours for the following season. In the depths of winter we see clothes for the height of summer, and vice versa. And twice a year, we see the gloss and glamour that surrounds the collections. What we do not see is the frenzied activity that goes on in the designers' showrooms after the shows.

It is here that the world's ritziest stores do their shopping, spending tens of thousands of pounds. Last October, while you were looking for thermals and woolly hats, the buyers were in Paris choosing spring clothes that are just beginning to filter into their shops. I helped carry the bags on two stores' shopping sprees . . .

Mirabelle Saint Marie, chief vendeuse at Azzedine Alaa, is not pleased with Rita Britton. 'You haven't even bought the best pieces in the collection]' she exclaims and throws on to the desk the order Ms Britton, who owns Pollyanna of Barnsley, has just spent four hours working on. 'You have missed the diamonds in the collection.' Britton smiles politely and prepares to dig in her heels. 'What did I tell you?' she whispers to me. 'They never like what I buy.'

But no one can really argue with Rita Britton's buying. In the past 20 years she has introduced Alaa, Donna Karan, Comme des Garcons and Issey Miyake to Barnsley - not the most obvious location for a shop selling designer labels. Yet, despite the famous labels, many of the clothes she chooses never make it to the pages of the fashion magazines.

'I never buy the catwalk pieces. I never buy anything I wouldn't wear myself,' she declares. She opts for basics that much of the fashion press would consider, for want of a better word, plain.

We next meet the following day at Comme des Garcons. Most stores have sent large buying teams, who work painstakingly with a salesperson and fitting model, trying on almost every piece of the collection. Rita, who turns up with her husband, her son and a student on placement at the shop, wanders up and down the showroom alone, getting a feel for the collection before she starts.

'Whenever I do a new collection, it's terrifying for the first half-hour, until the feel of it feeds through,' she says. 'My biggest advantage as a buyer is that I work on the shop floor. I look at the collection through the eyes of someone who has been buying for years. I know that when you're over 25, for instance, you get a belly, and you don't want to wear something that shows it off.'

Having scanned the rails for a first look, she begins to buy. Cost is rarely an issue. 'Of course it's a risk, but so is selling a jumper in Next for pounds 35. It's just a different market. They'll pay for it if they like it,' she says. But the process is intense. A mistake can cost a lot of money.

Luz, the salesperson at Comme des Garcons, arrives to look at the order sheets. 'You never take the things that everyone else takes,' she says, pulling out a few items she thinks Pollyanna should carry. After negotiation, a cap-sleeved dress in cupra (a stiff jersey fabric) with an elasticised waist is added to the order, a featherweight scoop-neck dress is not. 'They don't know my customers,' says Ms Britton.

This season, the fashion press picked up on Galliano's huge crinoline skirts. Joan Burstein of the Browns shops in London walks straight past them to the simplest pieces. Mrs B, as she is known, has been buying fashion for 23 years and Galliano since he began a decade ago. His latest, knicker-skimming kilts will not sell; his simple shifts will.

Anyone who thinks fashion is frivolous should watch a buyer at work. This is serious business: when a store buys four sequin-and-chiffon dresses wholesaling at pounds 800 each (to retail at about pounds 2,000), it is making a considerable gamble.

While John Galliano entertains a group of press and buyers with a video of his show, Mrs B works with her fashion director, Francoise Tessier, and contemporary buyer, Joel Burnstein. They walk along the rails picking out anything that catches their eye - first, a small collection of long, bias-cut dresses. On the catwalk, Christy Turlington wore one of these with a regal sash, and looked like a princess. But Mrs B wants to know if the sash and rosette are detachable.

After the core of the collection is chosen - shifts, Thirties-style dresses and delicate blouses - a few special items are added. A Russian jacket in white straw provokes debate. Mrs B wants to know about washing instructions and is told, 'It's fine as long as you don't wet it . . . light rain is OK, but heavy rain is difficult. It goes limp.' Nevertheless, it is ordered with someone special already in mind. Then there is a long cream coat bonded with lace, based on an Edwardian driving coat. Although this is pricey, Mrs Burstein feels confident that it will sell.

And, finally, those crinolines. Mrs B is not interested, despite fashion editors swooning over them. 'You'd need a carriage,' she says. 'You can't get in a car wearing one of those.'

Juliet Warkentin is editor of 'Draper's Record'. Azzedine Alaa and Comme des Garcons will be available at Pollyanna, 12 Market Hill, Barnsley, South Yorkshire, from the end of February; John Galliano will be at Browns, 23-27 South Molton Street, W1 from 1 March.

(Photograph omitted)