If you have a small chin, then you have a heart-shaped face. A heart-shaped face is larger on the top half of the face, between the cheek bones and the forehead. It then tapers down to a small chin, creating a heart shape. Some hairstyles are better than others to create a larger looking chin.
A short bob shape that ends just below the jaw line, or above the collar, will add fullness to the bottom half of your face. This is a good cut for someone who has wavy or curly hair. Let the natural waves frame your face to add femininity. The ends should end in a choppy wispy fringe, not a blunt cut. Avoid any style that has a slicked back look, because that will call attention to the wider top half of your head. Also, avoid any style with a heavy straight bang, because this will draw attention to your forehead and make the top of your head look even larger.
Long, wavy hair suits a face with a small chin. The long waves will add fullness to the lower half of your face. If you have long straight hair, use hot rollers or a curling iron on the bottom half of the hair to create curls and fullness. Avoid hot-setting the top of your head as this will only create more fullness when you don't need it. Long hair can be as long as you'd like, keeping the top half parted in the middle and falling from the face.
If you have a small chin and would like a short hairstyle, be sure all the hair isn't focused on the top half of your head. A short hairstyle with a thin top and sides, such as a pixie cut, would frame your face without adding unnecessary fullness. Be sure the hairstyle is wispy and not fluffy around your eyes. You can add some height on the crown by teasing or fluffing the top, if you'd like. This will elongate the top of your head instead of adding width.
Fringes that frame the face are well-suited for someone with a small chin and heart-shaped face. The fringes will frame your face and draw attention to your eyes, hide your forehead, and draw attention away from your small chin. The fringes should be included in the bangs. A fringe around your face will thin out the hair at the side of the head. Avoid a fluffy frame around the head, which will only add width to the top half of your head, which should be avoided.