At first glance, the ice-blue color and three-dimensional rosette appliqués create this gown's drop-dead impact, but the real secret is the seaming. A dozen panels of silk-satin extend from bodice to below the knee for a second-skin fit. No need for a bra with a bodice this finely constructed; featherlight tulle provides a Barbie finish. About $7,150, Reem Acra. Diamond headband, Tiffany & Co, 800-526-0649. Earrings, YNY Jewels, 212-203-4721. Ring, Tiffany & Co.