Get a good hairstyle! As a female, I am endlessly frustrated by the amount of guys i see around these days who have bad hair, and would look pretty hot if they had good hair.
Bad hair: usually shaved, bald, or just about any of the really short cuts that are sooo verry common these days.
Good hair: usualy a little bit longer looks good. have a hairdresser give it a nice cut. fringes often look hot- for example, a normal looking guy with a toned-down version of an emo fringe can look very hot.

The main thing is to create some kind of stylish image.

I think more guys need to know that girls are happy to talk to them. Don't worry about it too much- just be yourself. If it's around uni/college etc, you can just walk up to almost any girl you don't know and say ' hi, you i thought you looked like an iteresting person so i thought i'd come introduce myself. bla bla bla do you like .... so you're studying... oh thats nice etc etc' Having the confidence to approach girls adds attractiveness, and girls feel good about themselves and are flattered when men they don't know come talk to them.