Heh I use to be very shy, especially around girls. I just started to open up quite a bit through High School (still in high school, senior year). I never a had a lot of GF, but that is because I am not just looking for a date. Unlike a lot of people I know, I am actually looking for that "special someone" and I take my time getting to know that person.
Honestly, being yourself helps. Don't try to be someone you aren't. That just makes you seem fake, and quite a few girls/boys can pick up on that.
Ha I think I have found someone who is pretty "special" at the moment in RL...