Like Ive mentioned in another post, I play every hand like if I was posting and explaining the hand history here on the forum.
This has helped me alot because I have to explain every action I take to someone (even if that someone is not real), and I think when playing poker, people who read/play a lot, actually know what is the right thing to do in most situations. They just decide not to believe or trust themselves.

If I dont explain the hand, sometimes I'm fooling myself, calling a raise I know I shouldnt call, just because...well I wanna stay in the hand and see what happens, or I want to get lucky, or whatever. It doesnt matter, I dont have to explain my actions to myself.