Timelessly chic: a retro-inspired finger wave, like this one by Antonio Corral Calero, global creative ambassador for Moroccanoil. Because you want a tousled look, there's no need to stress if the waves aren't perfect—or if they fall out as the night goes on. (If they do start to fall apart, though, you can slightly dampen ringlets and scrunch them upwards with a hand towel. The towel absorbs excess moisture, so hair won't look wet.)
How to get the look: Comb a volumizing mousse through damp hair and rough-dry strands. Then wrap small sections around a 1-inch curling iron. Curl hair at the back of your head away from your face, and the pieces at the top and sides toward your face. (This change in direction creates the finger-wave shape.) Let set for a few minutes before gently brushing. "The more relaxed, the better," says Calero.
Pro pick: Moroccanoil Root Boost ($25, amazon.com).