I try to maintain a cheerful mien, but like anyone I do get very down from time to time. When I do I like to have a nice little wallow and then play music too loud (venting by proxy!), but after that? Meh.
Here’s a simple little song that tends to help lift me out of a ‘mood’:
https://www.youtube.com/watch?v=ItLJnlRF9vQ