The morning after, we realise our outfit was almost as embarrassing as the sales manager miming to "Jumping Jack Flash" in his underpants. Nevertheless, the next year we do it all over again. (My personal Waterloo was a red, stretchy mini dress that started just above my nipples and ended an inch below my VPL - in essence, a Wonderbra for the tummy that lifted and seperated every roll of fat.) I wore it once. The following year, I brought something similar in gold.
Celebrities make the same mistake, too. Joely Richardson, the gorgeously aquiline heroine of 101 Dalmations, recently attended the film's premiere in a white satin dress that made her look as if she was hiding a puppy under her slip. Glenn Close, at the same occasion, went for a lampshade in black satin and white tulle - more Mrs Pepperpot than Cruella De Vil. And society girls like Tamara Beckwith seem incapable of going out fully dressed. Why put on a party frock when you're wearing a shocking pink lace and turquoise satin underslip?
Christmas seems to encourage sartorial suicide, for `tis the season of fake magic. Just as a child you believed that Santa delivered Barbie's hairdressing salon, as an adult you want to believe that a spangly dress will mean you're not really a stone overweight with a spotty back. And this year it is worse than ever, given the fashionability of unforgivingly "glamorous" fabrics and styles such as spaghetti straps (hello flabby arms ), antique lace (makes even Helena Christensen look fat) and the deep V (goodbye bra).
"Gold satin has been going mad", reveals a spokesperson for Warehouse, which is also selling a stretchy halter-neck top and mini skirt in gold or purple sequins; a strappy dress in gold lace; and a halter neck dress in red or black satin. Meanwhile, black, gold and ruby beaded dresses have been flying out of Monsoon, in short, sleeveless and shoestring varieties.
The Christmas tree look is great for the shops, who can make a fortune on teeny-weeny bits of froth that don't even have sleeves. In the words of Lynn Elvy, director of Britain's largest image consultancy , House Of Colour: "clothes are priced up if they feature glitz".
For the consumer, however, such baubles are fraught with danger. "Black can make you look very sallow and old," says Gabriella Di Nora, manager of personal shopping at Selfridges. "Also, it's Christmas. Why, in God's name, would you want to go to a party in black? Very few people can carry off gold - it works best with auburn hair. As for red, if you are beyond a certain age, it will highlight certain capillaries.
All this is very sad, because we all crave a little magic. "Christmas clothes don't have to be serious", argues Kim Stringer, associate fashion and beauty director of Elle. "It's the one season you can get away with wearing anything". Sadly, as these photographs testify, this isn't necessarily the case.
One solution is to go personal shopping. "It's my job", says Gabriella Di Nora, "to find dresses that you can wear with a bra, that give cleavage, that hide an arm or a bit of extra weight." Her advice? "Never wear a dress that is too tight. Don't kid yourself - it's going to look horrible. All it says is I don't give a damn. And if the bra shows, even if it's a strapless bra, don't do it. It never works."
"Keep it simple," recommends Carolyn Robertson, a personal shopping manager at Dickens & Jones. "Just go for a great Patrick Cox shoe or a wonderful fake fur shawl. Otherwise you have to be prepared to work hard. Evening wear is very hard to judge on the hanger".
Lynn Elvy, meanwhile, has devised a complicated "Panto personality" test. If you identify with the Snow Queen, for example, you are probably a "dramatic" who looks good in shine rather than glitz. Cinderella, on the other hand, is the "ingenue" who is advised to go to the ball wearing lace. The fairy godmother is the "romantic" who can do low necklines and lots of sparkle. And so on.
Unfortunately, most of this advice comes too late. In my case, I think I'm a gypsy, a "natural" who just doesn't look good in glitz