25. The Schoolgirl Dress — Bored silly with all your old work dresses? We hear that. We say, be bold, pack up every single one you simply cannot bear to wear again, and invest in just one new one: the schoolgirl dress. Infinitely wearable and good-looking on practically every woman, the shape is a combo of '60s mod and '80s prep. 

Mulberry Nightshade Anglaise Dress, $935, available at Mulberry; Modekungen Collar Dress, $105.16, available at Modekungen.