There's so many different styles and haircuts one can have, but its important to know what what kind of hair style suits you, as it all depends according to your face shape.

Square Face Shapes
People with square faces should get hair cuts which allows it to show their strong jaw line, and therefore getting a hair cut with choppy ends with curls will look good. Getting layers on long hairs will also go well, as long as the layers start from the jawline and continued down. For those who have short hair can also go with the spiky cut.
However people with square face shapes should avoid bobs and blunt cuts.

Oval Face Shapes
If you have an oval face shape, you can generally get away with any face hair cut or hair style, whether its a shot or long style, straight or wavy style. One great advantage of having an oval face is that you can concentrate on your best feature and highlight that with your haircut. If you have a good bone structure, you can also get an angular bob that will show off your chin well, and for those who have noticeable eyes then go for the blunt or a side swept bang.
People with oval faces should avoid very short layers, which will add more height to your head (which is not required) and make your face look longer. People with heavy or curly hair should avoid having blunt cuts, and those with curly hair should never get a short haircut.

Long or "Oblong" Face Shapes
People with long and oblong faces should get brow skimming bangs, bobs which are chin lengthed are also ideal which give the give the face a wider look. Make sure the short look is shorted from the back so that it makes the look more interesting and different. Having curls or waves in your hair will also add width to the face.
If you have long hair make sure it isn't too long as it will bring your face down, you can add long layers to the face which hit the nose, chin and collarbone. You can also have a v-shaped cut so that the long hair length stays at the back.
Avoid having hair longer than the collarbone and super short hair cuts.

Heart Face Shapes
People with heart shaped faces have their chin as the focal point, so therefore drawing attention to the eyes and cheekbones with a sideswept bang, a short part and hair which begins to fall below your jawline or just at the jawline and a brow grazing fringe is suitable. People with long hair should keep layers which are long and soft.
Heart face shaped people should avoid short, blunt cut bangs and choppy layers.

Hope this thread will help you all out there you have trouble knowing what kind of hair cut to have.

This is great information. I read this in a magazine when we were on vacation and then my husband and I were trying to figure out what shape face I have I think we agreed it is oval or round~ still not quite sure.

The best way to find out your face shape is to take a lipstick, look into the mirror and draw around the outline of your face onto the surface. Step back and look at the shape.

I'm an oval.

Wow, thats sure a great way to know what shape my face is. I have tried all sorts of hair cuts before but my other half always approved this short bob hair cut for me...

Thanks for the idea. I am going to try this. Always wondered what shape my face is...

Thats a nice piece of information regarding the hair styles and cuts depending on the face shape and structure, it often becomes unfit for people who do hair cut without inspection of an expert. I think this will guide people who cut their hairs by themselves.

I'm curious though.. does lipstick come off the mirror easily? I think that's an awesome idea. I've only seen people draw with lipstick on mirrors in music videos. Like.. The Veronicas or Beyonce. lol Sounds fun to me