"A black-tie wedding is all about elegant dresses and ornate jewelry. You need an equally dressed-up hairstyle for balance," says Hawkins. Whether worn simply or with a jeweled tiara, this updated, less stiff version of a sixties bouffant style is ideal for evening.

Edwardian-style diamond necklace, Fred Leighton, price on request; 212-288-1872. Taffeta gown with draped bodice, Vera Wang, $4,990; 800-839-8372.