The biggest realization of my life was when I was 22. My room ate and i were tired of getting nowhere with girls, because we were nice, occasionally nervous, etc. It's alarming how much action you can get when you are willing to just hit on girls. They respond to confidence. Sure, you'll get some rejection; but a decade later i still think of the time I asked for the number of the girl working at the shoe store in the mall. The hottest chest i have ever seen in my life, naked on my couch two days later, all because I stopped myself after walking out of the store, smacked myself on the cheek, and went back in there and started chatting.
Once you recognize that it doesn't matter if a girl shoots you down, you will see that its not so hard. The key is being confident enough to not give a fuck.
Aside from confidence; it's obvious stuff. Dress sharp, get decent hair, bathe, lift weights, etc., all these things can only help... And obviously, you have to possess basic conversational skills.