Round
As far as haircuts go, the best ones according to your face shape are cuts that will help to elongate the look of your face. That being said, longer layers around the face rather than a short cut will look best. If your hair is short and curly, a flattering look would be to allow your hair to fall below the chin and try to avoid cutting too short. Middle parts and deep side parts work great because they elongate your face.
Square
Curly hair tends to soften this angular face shape, so your curls, coils, and waves are only enhancing your beauty! With this shape side parts work well, especially soft side swept bangs.
Long
Short hair works well with long faces because well, your face is long. If you have long hair then I suggest giving your hair more volume and keeping it off of your face and more to the sides. I have a longer face shape and this works great for me. Middle parts or no part at all looks are great on this face shape.
Oval
Any haircut or part will work for your face shape. Middle part, side part, long, short, asymmetrical, or layered, anything goes with this face shape. This face shape is often coveted, so make sure you experiment with different parts, haircuts, and styles.
Heart
Because your face is a heart shape, you should play up the upper parts of your face, namely your eyes and cheekbones. To do this, layers work well. A side part looks good on heart shaped faces because it is a good juxtaposition to your pointy chin.
So there you have it! Those are the best haircuts and parts for your face shape, but do remember, these are not the be-all end-all. They are just suggestions you can use to enhance your beauty. If you want to go against the grain, then by all means do it! You may already abide by some of these suggestions and not even know it—I know I did. If you ever noticed certain hairstyles you do look better than others, it is probably because you are subconsciously following these very simple guidelines.
How do you part your hair?