Style police; No accounting for taste

It's a familiar sight in London's South Molton Street. A weary woman of independent means, dressed in a smart Jean Muir suit, takes the weight off her Ferragamo court shoes and slugs back a glass of wine. She marches across the street into Browns with a look of grim determination, then totters out looking like the Widow Twankey in the latest chiffon, ruffled skirt. Yup, we are in the season of the Summer Sale.

The sales are not for the benefit of the customer. Anything with a slashed pricetag is a mistake on the part of the buyer. It's the stuff people with cash to burn didn't bother buying. "Before you reach for the credit card, ask yourself whether you'd buy the piece at full price," advises Rita Britton of Pollyanna. Only a real label queen will buy a devoree, velveteen, Jean-Paul Gaultier sarong on sale - remember, people don't see the label, they see a sad hippie.

But Style Police is as susceptible to a bargain as the next man, so, here's our sale shopping guide.

Don't bother with middle-market sales. Marks & Spencer won't put white T-shirts on sale. You'll just get gingham short skirts and citrus brights that only Food & Drink's Jilly Goulden would wear.

Few can afford designer mainlines - the sale is the one crack we can have at labels. Classic designer wear can be a steal if there is a slight fault, like Liberty's Georgina Von Etzdorf scarves. The stock is bought in for the sale and the fabulous chiffon/velvet devoree stoles are down from pounds 150 to pounds 99 because the colour is slightly off-palette or there is a minor fault in the pattern. Who will know?

Liberty is the best sale. It will show you just what women aren't wearing. For example, Ralph Lauren's sale rail is longer the Maginot Line. But in the middle is a perfect, navy, crepe shift with white detail (down from pounds 370 to pounds 185). Never resist the temptation to rummage. Always look at who isn't on sale to clock the hot labels. Then see who is half and who a third off. If the full-price stock is similar, perhaps the sale piece is an off-size or slightly damaged. Buy it.

The most covetable sale pieces are the "I'm not paying" dresses. Pearce Fionda makes the most delectable jackets, smart tops and evening gowns since Madame Vionnet. At pounds 1,555, the black, crepe, evening dress is twice the amount of a mortgage repayment. At pounds 779, it is still expensive but justifiable. The same goes for John Galliano. A price tag of pounds 1,435 for a broderie anglaise short jacket makes the customer feel like Imelda Marcos. At pounds 717, it's more Princess Di. The scratch-your-eyes-out piece in Liberty's sale is a Jean Muir navy crepe dress (from pounds 605 to pounds 400). On your marks...