One of the big things that separates a winner from a break even or marginal losing player is the hands they lose with. Everybody tries to maximize their wins, but when you lose big it offsets that and becomes really aggravating. I played 3k hands of breakeven poker and I know there are lots of people who have had longer streaks, but the difference was most of it was due to me winning big but losing big as well. Recently Ive been spending my time on reading what my opponents have and to know when Im beat. I found there are some hands that I overvalue preflop, and then I also realized that I have a hard time laying down an overpair or two pair when its pretty clear that Im beat.

This is a good thread over at 2+2 that gives advice on how to find your leaks using pokertracker:
http://forumserver.twoplustwo.com/sh...fpart=all&vc=1

Try analyzing your own play, post some hands here and see how your thought process stacks up against what other people think, and then post what you think about other people's hands.