I don't go to many clubs because with classes and everything I rarely have any time. I am decently confident and can hold a conversation with someone cute I meet in a cafe or a library. But there are just too many good looking girls and I feel tempted to ask like 5 girls daily just so that I don't 'regret not talking to that beautiful chick' in the future. How do you guys decide which woman to approach?

A few weeks ago, I was sleeping with this grad student (7-8 years older than me) recently and she broke things off with me, presumably because I was being needy and was maybe more invested than her. Retrospectively, I may have come off too strong and that must have been a turn-off. I am trying to improve my approaching girls on the fly game and have so far been fairly unsuccessful at it. How do I decide whom to approach? Any help would be fantastic.