Poker Tilting is technically losing your reasoning whilst playing; that is, not approaching the game with a strategy and going only by 'feelings', hunches and moods.
Notice early warning signs of going on tilt (such as good wins which make you feel heady and bold, or maybe even rowdy players).
Before you actually GO on tilt, recognize that some events may get you distracted and upset but respond to it by resisting the urge to start playing wildly and unreasonably.
Leave the table for a while, if neccesary; if you can resist (AFTER you have learned to recognize and handle your feelings of going on tilit) try standing up for a hand or two.
Learn that you are the only one to control yourself.
Recognize that if the game conditions are not to your liking, you should go elsewhere, distract yourself.