The Jackie O shift has held court in the dress department over the past few seasons, and for good reason - it was easy to interpret, flattering to most shapes but it was essentially a smart dress. This summer the shirt dress is the big story, and although it has all the advantages of the Jackie O it is even more versatile. In slinky jersey it can look smart, in denim or cotton it can be a throw-on summer dress, it can be worn over trousers, shorts, on its own, in bed, on the beach, some of the tunic-shaped ones (such as the Whistles one featured here) would be perfect for expectant mothers or those of bigger proportions, and the button-up style is good if you're breast-feeding. It is an invaluable buy and available from every high street store worth its name.

White cotton sleeveless shirt dress (above), pounds 100, from Liberty, Regent Street, London W1, tel: 0171 734 1234, and Harvey Nichols, Knightsbridge, London SW1, tel: 0171 235 5000. Flat snakeskin sandals, to order from Gina Shoes, tel: 0171 235 2932.

Liberty print floral cotton shirt dress (main picture) with matching belt, pounds 75, Liberty Collection, Liberty, as before.

White tunic-style shirt dress (top right), pounds 125, from Whistles, 27 Sloane Square, London SW1, and branches, tel: 0171 730 9819. Flat snakeskin sandals from Gina Shoes as before.

Black rayon jersey shirt dress (bottom right), pounds 26.99, from Oasis branches nationwide, tel: 0171 377 5335. Black suede platform sandals, pounds 34.99, from Next branches nationwide, tel: 0116 284 9424. Belt made from chain, stylist's own.