Self control is extremely important. In all aspects of life.
My rankings:
1 - Reading other players. Knowing the hand an opponent has is an advantage that is trumped by nothing else.
2 - Patience is so important. Poker is a game of waiting. If you aren't willing to accept the fact that you may go an hour or more without winning one put, you won't profit in the long run.
3 - Self control. Having the discipline to fold strong hands and refraining from
bluffing can mean the difference in winning or losing any game.
4 -
odds. Knowing your outs isn't always helpful and can actually keep you in hands that turn out to be a loss. But it can also help win pots. This goes hand in hand with self control. Sometimes you should fold despite favorable odds.
5 - Body language. Don't let others tag you as a fish who has all kinds of
tells.