Don dark gems and sky-high stilettos, and pouf!—it's the ultimate night-out dress. Burgundy chiffon strapless dress with bubble hemline, about $250, Badgley Mischka Bridesmaids. Cubic zirconia stud earrings, Carolee. Onyx quartz double-strand necklace, Turq Bridal. Oval stone-and-crystal bangle, Amrita Singh. Black patent bag, Lorelei. Slingbacks, Stuart Weitzman.