The first rule of sunglasses: stick with a classic—simple shapes like the aviator or wayfarer in discreet blacks, grays and tortoise shells. The second rule: know what frame suits your face. The unmentioned rule? Pony up the cash for a decent pair and you'll never accidentally sit on them again.

Persol, $255

Round Face

Add definition to a curved face and full cheeks with a rectangular pair that contrasts the roundness. The angular shape also makes your face look leaner.

Gucci, $275

Carrera, $120

Oval Face

Balance out a longer, thinner face with wider frames. If you keep the proportion in check, you'll be able to pull off larger, more retro shades.

Club Monaco, $89

Randolph Engineering, $99

Egg/Triangle Face

Whether you have a small forehead and a strong chin (egg) or a broad forehead and narrow chin (triangle), look for rounded frames. Gradient lenses add even more balance to your face.

Oliver Peoples, $325