For an authentic emo style -- a trendy "emotional" hairstyle that's really popular among teenagers and young adults -- it's usually all about having super-long locks or a closely cropped cut. It doesn't have to be that way, though. Even if you have mid-length hair that is neither short nor long, you can still achieve the signature emo look. As long as you opt for the right hairstyle, there won't be any confusion as to what sort of style you're going for.
A hair pouf is a more casual emo-inspired style. It's got a lot of volume and makes your mid-length hair look uber-thick and voluminous, no matter how limp and lifeless it might usually be. Pull up a section of hair at the top center of your head, about 3 inches wide. Tease around the roots of all this hair, creating lots of lift. Rake softly over top of the hair to get rid of any frizz -- keeping the roughness underneath the hair to maintain that oomph -- and pin it against the top of your head with a couple of bobby pins. Push the hair forward slightly first to really maximize your pouf.
The sideswept look is totally emo-styled, with the front section of your hair draping across your forehead. In most cases you would want to keep your hair out of your eyes, but when you're trying to get this look, it's exactly what you want. Hence the use of "emotional" for this bold, dramatic style. To achieve this look, make a deep side part as far as you can to one side, while your hair is still damp. Blow-dry your hair to this side with a round brush until it's completely dry. Flat-iron over the hair, styling it in the same direction, then finish by running a dab of smoothing serum over your strands. This basically seals in all of that hard work you put into straightening and keeps your hair super sleek and straight.
If you have layers in your mid-length hair, you can still achieve an emo style, no problem. Part your hair far to one side and flat-iron over the front and back sections. With the shorter sections around the crown of your head, work a bit of pomade through the hair to create some texture, and pull the hair away from your head with your fingers, twisting slightly at the ends of each section to create a twist and keep the hair spiked up around your head.
You don't have to go with an all-out hairstyle just to get the emo look. Flat-iron over your hair to keep with the stick-straight emo signature hairstyle, then add in a couple of colored hair extensions. The last thing you want in this case is subtlety, so opt for the boldest, brightest colors you can find. Hot pink or black in blond hair; platinum or red for darker hair tones. Simply by adding a couple streaks of colors, you get a punk-styled look that is definitely emo.