The first step is to realise, that this is even happening. So by doing that you are already on the right track. The next step is to use various meditation and mind control techniques like deep breathing, positive thinking and so on and so forth. And also be mentally prepared. Nathan Villiams have made many videos on Youtube about bad beats and tilts, and one of his suggestions is to say to yourself "this session I am going to suffer at least 10 bad beats, and I am ok with that" before you even start playing.
If the tilt happen anyway, and its bad, then sit out for 5 minutes and walk around the house, make a cup of coffee or whatever. This does cost some chips in tournaments, but unless you are very short and deep in the tournament, its usually not that much of a deal, and its less bad than dusting away all your chips due to bad tilted play. Also if this was nessesary, you should definitely plan to end your session as soon as possible and take at least an extended break for several hours. So stop adding more tournaments and focus on finishing those, you already have running.
Finally its important to try to focus on the process rather than short term results. I am personally in a bit of a slump at the moment, having played around 3.000 games (mostly SnGs) on
pokerstars with no results. And the change, I implemented recently, is to hide the balance in the cashier to force myself to only look at it once a week rather than after and even during each single session. And I am also not going to look at results in my tracker more often than that.
Its human nature to pay a lot of attention to, how we did in the latest session. But if we are using proper
bankroll management, there is really no need to know, if we are up $30 or down $50, because we should have plenty of money to play the games, we selected, and adjusting our game selection once a week should be more than enough.
What we should do instead is to spend more time studying and reviewing our hands. The way, I personally do that with SnGs is to import all the hand histories into ICMizer and let the program look for potential mistakes in push-fold spots. If you play cash games or MTTs, the best way is to find the biggest losing and winning hands and look at, how you played them one by one. And also review your final tables.
Track your poker statistics and avoid the sharks. SharkScope is the most complete database of poker tournament results available and covers virtually all online poker sites.
www.sharkscope.com