Part of turning pro is having enough experience to really understand the nature of variance and what your edge is long term.  When you've beat the games for a certain amount of time it gives you enough confidence to not let downswings or bad beats effect you.  All a pro poker player thinks about is how make the best possible decision on every street not "no club no club no club.... fuck another bad beat".  Thinking about results is a waste of energy the only thing that matters is decisions.  Once you have achieve this mindset, getting bad beats isn't tilting, only playing bad is tilting and good players quit when playing bad.  Easier said than done but thats why more humans fail at this game than succeed. Our brains are constructed to learn and adapt from results, this doesn't always hold true in poker at least in the short term. 

MatAA already nailed it but I can add 1 tip: take a pen and paper. Now be honest with yourself. Note after how many bad beats/bad plays or every time you criticize an opponent per session you start to tilt. Say for example that you start to tilt after number 5.After every bad beat/bad play or every time you criticize an opponent, note an X on paper. If you reach 5 X's just stop playing until you have totally calmed down and then start a new session and repeat. This really works for me. I started with 5 X's and I am now using 10 X's.  Gl 

The thing that helps me most is simple sarcasm! Like if it's a case of them hitting a 2 outter on the river i'll simply scoff and say to myself "Fantastic call with T7off there...well played you lucky nitiwit!!" and take comfort in the fact you are getting it in as a favourite and it's the fish that have/need to get lucky.I think that's totally different to getting angry or annoyed about it and reacting by playing like a goon (which does happen every so often obviously, we're only human after all). It's one thing to criticise an opponent (or even your own play) but another to acknowledge his poor understanding of how to play the game and see it for what it is.As long as you can see his lucky river suckout as poor play you should start to realise its this kind of play you want from your opponents and the bad beats come as a result of this. 2hotty420

Honestly the fact that I can't play poker as much as I like now has made me realize how much of my good anti-tilt strategy was the ability to put in a lot of volume. Without that, I feel the same skittishness about short term results. So one thing to look at is working on how good you are at putting volume in and teaching yourself to do that.