Do something that you're good at and enjoy doing. For example, if you're
a fantastic dancer, set aside some time to dance. You'll improve and you'll
also feel good that you're doing something you do well.
Increase your physical activity to boost your mood. If you enjoy working
out or playing a sport, do that; if you don't, use the stairs instead of
the elevator. Or, walk or bike short distances instead of driving or riding
the bus.
Do something good for someone else. It can be as easy as calling your
grandmother or as much as starting a collection of money to support
research to find a cure for cancer. Other examples might be volunteering at
an animal shelter or soup kitchen.