On the formality meter, a cocktail wedding falls somewhere between a casual garden party and a black-tie reception. "Your hair should seem polished but not too grand,” N.Y.C. hairstylist Nathaniel Hawkins. A crystal-encrusted headband makes this off-center chignon party-ready.

Silk-ribbon headband with Swarovski crystals, Maria Elena Headpieces, $300; 305-717-3404. Earrings of 18kt white gold and pavé diamonds, Jamie Wolf, $9,500; 212-833-2086.