Informal celebrations call for less constructed hairstyles than more formal affairs do. This flowered tiara makes an otherwise casual look seem festive.

Antique-jewelry tiara, Lynn Kiracofe, $900; at Lara Hélène Bridal Atelier, 212-452-3273. Sterling-silver earrings with mother-of-pearl, Annette Ferdinandsen, $200; 212-352-1333. Floral jacquard gown, Vera Wang, price on request; 800-839-8372.