If you have a wide forehead, like Kylie:

These '80s shades are back (to the future) in a big way. Accentuate your face shape with a straight-edge frame, like this pair from Foster Grant. To complete the look, just add Michael J. Fox.

$12 at Fred Meijer, Target, Walgreens and Stop and Shop; or visit FosterGrant.com for other retailers