If you have the passion for playing poker the most important thing that you must remember is that always be a happy looser but at the same time if you win, be humble. When you are playing try and play small pots so that if you loose, there are small amounts to loose. Make sure you are well prepared and ready to play and only then start playing.
Never get dragged away by the strategies of your opponent or loose your temper and control. Also do not worry about the money you loose unless it drives you crazy. This is because while playing poker you are not going to win always and so be prepared for the losses too.
You must understand your position in the game and do not play every hand. Keep in mind that paying just to be in action is not worth because playing more hands can lead to more losses and not gains. If necessary make many folds and try not to drink too much while you play. Always avoid playing if you are drunk especially if you are in a casino.