The number one thing I do is the Alexander technique. I urge you to give it a try. Find a teacher in your area and go for at least ten lessons (it takes about ten private lessons to actually get what they're saying, I was really resistant at first because I'm a natural skeptic, but once you get it, it's amazing). http://www.amsatonline.org/alexander-technique
I exercise. The two best exercises to boost my endorphins are push-ups and running. As a man, working out my chest, shoulders, and arms really releases endorphins. If I do push-ups to exhaustion, which is no fun, I feel great for hours, which IS fun.
I play very amateurish classical guitar. I've taken lessons for years and I love it. Trying to figure out a new piece just from the sheet music takes all my focus and I lose track of time.
Photography. I'm a writer by trade, so writing actually induces my anxiety, at least at first.by the time I've produced a usable draft I'm happy, but at first, ugh. But I have no stakes in photography. It's just a creative outlet. I also never use an automatic setting on my dslr. I try really hard to figure out the settings on my own, which is like reading music, it takes all of my concentration which leaves no room for anxiety.
Oh, I don't do this often enough, but sometimes I'll work on a puzzle with my older son. I should do that more, because puzzles take a lot of concentration, but are really low stakes. Unfortunately I have OCD so if we are missing a piece it really, really bothers me. Though I haven't tried a puzzle since I started prozac, so maybe it wouldn't be as bad now.
I want to try Brazilian Jiu Jitsu. Does anybody do that?