So.. how exactly DO you talk to women?

I'm 21 and I've only had two girlfriends so far. The second of which being for 3 years and that ended about 6 months ago when I was basically cheated on. Anyways since I've only had 2 girlfriends and it's been close to 4 years now since I was last on the dating scene (when I was 17 geez..) I really have no idea how to talk to women in college! I've tried to pick up on signs that they want to talk to me, such as I will look them in the eye and smile but I don't even get a smile back and that just makes it awkward. I'm told by friends that I'm a pretty decent or even good looking guy so I'm not sure why I don't even get a glance or smile from women at all? Also I'm against drinking and before marriage and I hate going to bars/clubs because all the people there are there to party.. i greatly dislike party goers and just that whole environment in general.. so it's already hard enough to try to meet women because if I go to those kinds of social gatherings they will be full of people that I don't get along with. But I'm also atheist so don't say to go meet girls at church. Where can I even find women with values like myself?!