Mine - Its not that great but whatever - I taught myself a language through song translation.
I was heavily into German Rock music while I was in highschool, and I would translate the non-English songs for fun, with google. By graduation, I was almost able to speak the language. Not fluently, but I got by from the people I knew who actively spoke the language.
Its been 6 years and Im not even interested in the music anymore, maybe from constant repetition of the same 4 albums over and over.
Anyway, Whats yours?
First you have to have a genuine desire to change. I already had that for various reasons. This is harder than it sounds.
Then you need to have some sort of belief that what you are going to use has chance to work.
I was given an example of a little trick some actors used to calm themselves. Little gestures you might see and think nothing of. The example I was given was someone touching their earlobe. Apparently they used this a a trigger to bring back memories of the character they we trying to portray. Whenever they felt in the groove they would touch their earlobe. So when they were on set and weren't feeling in character they would touch their earlobe and the feelings of nailing the character would flood back prompted by that trigger.
In that way I was introduced to the concept that your feelings dictate behavior but that also your behavior can dictate your feelings. I the made my own trigger which I use to this day. I touch my thumb and index finger together when I'm feeling out of my depth and lacking in confidence. Because I taught myself to do this at times when I was actually feeling confident the feelings came flooding back. My back straightened, my eyes made contact with theirs. People started noticing that I was more confident and said so. The finger thing is now a habit of mine and self-serving/reinforcing.
So I started studying CBT in depth. I tried to avoid the obvious cash in self-help books and went for full on academic studies on it. You can train your mind but you have to believe your mind is your tool and not the totality of your existence. I also believe CBT can be a trap if you let it dictate to much of how you live as well. If your dog(your mind) is being a good boy you can just let him be most times. Tell him he's doing well and get on with the here and now.
It was hard work though sticking to the plan.