How to dress: Don't get your knickers in a twist

Fashion has its first New Look of 2010: underwear as outerwear. This may seem a bit idiotic, considering the weather outside, but therein lies the brilliance of the idea. ­Because however sumptuously stocked your knicker drawer, it will not (unless your name is Gaga ) furnish you with an outfit you can leave the house in. For Gaga, and wannabe Gagettes, underwear as outerwear means big knickers, a corset belt and a bra top; "covering up" means a transparent tulle petticoat. But in the real world, it is more about perfecting the art of trompe l'oeil than about getting in touch with your inner artist's model. It is a look that calls for discretion. There was a strong retro tint to catwalk lingerie in Paris and Milan. The transparent element came from webbed stretch elastene rather than Ann Summers-esque sheer chiffon; shaping came courtesy of stiff faux-whalebone boning, not school-of-Wonderbra padding; boudoir shades of black and powder pink dominated. Lingerie is like scent: a hint has an aura of mystique and sophistication, but a full-on blast gives the opposite impression. Lace panelling, elastic shoulder straps, even hook-and-eye clasps: such details draw the eye ­because we expect them to be under wraps. Even half-glimpsed, you can guarantee they will be spotted. And many of your audience will have no notion of your oblique references to the latest film noir-influenced Dior collection. Therefore caution is ­advised. Underwear as outerwear is no excuse for showing your knickers. • Jess wears dress, £59.99, by Urban Outfitters . Cardigan, £49.99, by Zara , 020-7534 9500. Boots, £165, by Russell and Bromley, 020-7629-6903. Tights, £15, by Falke at mytights.com . Jewellery, Jess's own. Photograph: David Newby.