Ditch the sack. Body-conscious—but not tight—clothes are always best, whatever your size. A figure hidden in yards of fabric always looks bigger.
Think vertical. Seams, stripes, piping, or a deep V-neck all stretch you out. Be wary of anything horizontal.
Equalize your proportions. Pear shapes should offset a bigger lower half with details that broaden the upper body (flutter sleeves, boat necks); well-endowed women can downsize their busts with simple tops.
Disguise thighs. Minis can be tough because they bisect the leg where it's biggest. I'm a firm believer in skirts that hit at midknee, where your leg is slimmer.
Emphasize your waist. In fact, emphasize all your strongest features. Use color and pattern to bring the gaze to shoulders or good legs (and divert it from other areas).
Avoid flimsy fabrics. Materials like gabardine or stretch cotton—especially in tailored form—give the body structure. Thin fabrics show every bulge.