A coworker and myself actually give presentations on burnout, vicarious trauma, and destressing. You have to find something that you really like to do. I love to read the dis boards, but I don't post when I am stressing, I only go from post to post reading. I only read fun stuff, not anything that is venting.
My coworker paints her nails. She has the most beautiful hands and fingernails. You would think that she had them professionally done. She said one time that she can spend up to two hours doing them. When she needs to chill, she paints away.
One coworker lights candles. One bakes sweets. One listens to her radio as loud as possible.
Basically, you need to find what calms you, and save it for those stressful times.