Mixed bucket for me. Sometimes I feel emo and want to be sad, so I wait it out. Usually I'll talk to Blisscakes and grab a cuddle/chat. Othertimes I'll go straight to comedy city. Nothing like a few episodes of Family Guy/Simpsons to lift the mood. Pet the dog (not a euphemism). Think of the less fortunate.
More obscure methods include pushing Bliss down the stairs, throwing rocks at children on their way home from school and reading the joke about the girl on the swing with no arms.
Normally i just wait it out,like i am at the moment,eventually the sadness will pass,or be replaced with another emotion.
Depending on what has caused the sadness,is a factor as well,some things will pass in few hours,some can take weeks even months,in the last week or so i have gone from sadness to anger to something that resembles my normal state.
When I'm sad I give myself the chance to really feel it instead of fighting it. I listen to sad music, for example.
Then when I think I've spent too much time being sad, I talk to myself and say "mourning is over! now let's go have fun". I surround myself with cheerful people (being with my kids is a plus, they're always cheerful). I put on upbeat music and sing/dance to it.