The flannel nightie your aunt bought you as a shower gift isn’t going to cut it for the wedding night. And since lacy underthings may not be a world you’re altogether familiar with, get help from an expert like Valerie Lucas of Coup de Foudre Lingerie, 202-393-0878, coupdefoudrelingerie.com, in Penn Quarter. "Brides should always feel sexy, but more important, they should feel comfortable," Valerie says. Chemises and full-length gowns like this "May" chemise, Jonquil, $188.90, are equally elegant and ultra-feminine. "Your height will determine which works best for you," she says. "But normally, the taller you are, the more length you can add." Look for one with gorgeous lacework.