I don't even try to, and I have many (at least for someone like..me/us?) freinds. Honest.
My now-best-friend approached me, and we talked about soemthing I didn't even remmeber, and we became friends. With the others, we simply are around each other. Like, say, K (shortened, I'm so clever). I met him by just being near him at lunch and in class. Eventually, we talked, and then (I forgot to stress this) AFTER A VERY LONG LONG LONG PERIOD OF SLOW, GLACIALLY SLOW, LIKE THE MOVING OF THE UNIVERSE FROM THE EPICENTER OF THE BIG BANG SLOW, we became friends.
So...I suggest being you, they shy you, anything, not that "Be yourself, and by that I mean be more social, dammit" stuff. It takes freaking forever, but it works.