Surround yourself with happy people. Do the opposite to prevent yourself from hurting or feeling sad. To deal with how you feel; try to talk to friends who help and understand why or how to correct your sad moods when you are happy.
I try to listen to a cathartic song that is somewhat relevant to the sad situation I find myself in- could be sad, could be happy. Depends a lot on the lyrics.
i get out of my house and if thats not possible I watch whose line is anyways episode. Especially season 5 episode 5. If that does make you happy or get you out of your sad mood. NOTHING ever will =D
I listen to instrumental.