When choosing a new haircut you need to choose one that flatters your facial features and shape. To find out what your face shape is use a bandana or something to pull the hair completely off your face and look in the mirror analyzing the following features:

Size of your forehead
Width between cheekbones
Dimension of the jaw line and chin area
Determine your best facial feature i.e.; eyes, cheek bones or jaw line

If you have a round face you need long locks along the sides of your face to create length. If you have a long face you need a blunt cut below your chin to create width.
Full curly hair creates width and fullness while straight shoulder length or longer locks create length and narrowness in the face.

If you have a large forehead you may consider bangs or fringe. A side swept bang adds softness and disguises a large forehead. If you have a small area between your eyebrows and hairline you may want to consider very short fringy bangs or none at all. You want to make this area appear larger.

If you have a wide face, a lot of space between the cheekbones you may consider lots of layering around the perimeter of your hairline to soften, lengthen and minimize the space between your cheekbones.

For the narrow, receding jaw line you may want to accentuate it by creating a strong line such as a chin length bob to create width in this area. On the contrary if you have a very strong square shaped jaw line you may want to wear your locks shoulder length or create lots of soft layers from the mouth to the longest layer.

If you still don't know what would look best on you go for lots of layers that direct the eye towards your best features, such as your eyes, lips or jaw line. Wearing hair that is just below the shoulders or falls right at the collarbone is flattering on any face shape. Keep the back rounded not straight across and the layers flattering your best features. This haircut is a classic no matter what your face shape, it is versatile, sexy and youthful.