The cuts that will flatter you―and those to avoid.
Look for: A skirt that gradually flares out in an A formation from the natural waist to the floor, highlighting the narrowness of the midsection and floating away from the hips and thighs. (Sturdier fabrics, such as duchesse satin and taffeta, are especially effective, since they won't cling.) A spaghetti-strap bodice or a V neckline will also showcase a more slender upper body.
Keep in mind: A classic A-line silhouette lends itself to formal weddings, but it can also be dressed down when made from a more casual fabric, like eyelet lace or raw-silk shantung.