Whenever I get stressed, which can be often, dependent on what's going on at the moment, doesn't matter if it's negative or positive, I usually get up and walk away for a bit. Sometimes I go outside to my garden, sometimes I just pick up something else to do inside (I'm self employed and work from home.)
If that doesn't work, and really it's just a diversionary tactic of focusing elsewhere and clearing my mind, then I sit down with a good old cup of herbal tea and listen to music, something mild like New Age or whatnot.
Really, negative or positive, stress is just a state of mind we get ourselves worked up into. It's something you have complete control over ~ if it's negative, ask yourself is it really worth it to get worked up over it, and what will working yourself up over it actually accomplish? If it's positive, the same thing, although that seems to me to be more instant euphoria then you come crashing back to earth and start worrying.
The energy that gets put into stress can be channelled into so many other energies which is why it's JMHO that we have complete control over stress. I may not be right about this, but it's worked for me ever since I convinced myself. LOL