If it's something that can be talked about, I try to get the matter out into the open and discuss WHY I'm feeling the way I am as to WHAT led me to such stress.
Otherwise, if it's just because of something with me ... I tend to do things that help alleviate stress ...
exercise or dance
listen to mellow music
visit family or friends (you know, happy, pleasant encounters ... unless, it's family or friends that I'm stressed about)
take time-out for myself (shopping, go for a cruise in the car, relax in the tub, or have a glass of wine to unwind)
same