Lots of ways, but I haven't found anything that works long term.
I'll list most of them below, hope you find one that helps. ^_^
*Texting my bf or chatting with friends to vent a bit and get their take on things going on in my life (and often, to provide the same thing in return for them when they need it).
*Visiting picture sites that make me smile like dailysquee, totsandgiggles, icanhascheezeburger... etc.
*Going outside and beating a tree with something squishy so it doesn't hurt the tree, then giving the tree an apology hug.
*Music...lots of music.
*Playing video games, either really cutesy ones like Harvest Moon or really violent ones like Metal Gear (shooting pixelated bad guys is almost as good as bubble wrap is).
*Sit down with some tissues and just cry until I'm exhausted when I'm so frustrated with something I can't get over it.
*Going for a long walk or ride on my bicycle to get fresh air and get away from the house for a while if the house or people in it are what's causing me stress.
*Forgot this one, but also a little safe self bondage and impact play like spanking... or masturbation...good for the soul.
*Meditation or a nice cup of tea and a snack outside when it's warm enough...early in the morning so I can just enjoy the sounds of nature and preferably by a small brook.
*Cooking or baking, usually cupcakes, cake, or cookies; dunno why but I love it.
*Playing with or cuddling our dog, pretty much an instant stress buster even if it's only for a few minutes.
*Working on one of the dozens of craft projects I've got in progress at any given time.