Over the last years I've been consciously trying to address stress more by avoiding it. This is prevention, opposed to just working it out once I've got a case of it. In practice, this means adopting a "life's too short" perspective and just skipping emotional involvement in things that used to light me up.
One big factor is rejecting political "causes". I used to be all about "church and state", "gun rights", etc. Now I just don't get into it anymore. The older I get and the more I read, the more I realize causes are a constant and have been throughout history. And there's always more than enough people that willingly step up and provide the constant level of anger and frustration.
Part and parcel with "causes", I've become very selective about how much "news" I take in. I'm convinced that the "media" are devoted to not much more than sensationalizing every morsel of bad news they can uncover... or even create. While I used to see being "informed" as sort of a civic duty, I no longer feel that way. Humans evolved being able to handle bad news from within walking or horse riding distances. That was a manageable quantity. Now, we are bombarded with it, 24/7, from every part of the globe. It's just too much. I may be less informed, but I'm a damn site less stressed.
Then there's being more patient with those around me, and with myself. Lot's of work to do there.
As far as blowing off stress once I've got it... I try to either solve the problem or let it go. And there's all those escape tools already mentioned that I use too: reading, working out, mindless tv, fixing something.