I sometimes go out for a good blast in my car, there's a long stretch of country road near me that's good for a thrash.

Watch something funny or comedy related or something on TV you enjoy.

Go out for a casual chilled out walk, usually down by the beach, looking out at sea or watching the waves crashing back and fourth is quite releaxing.

Number 1 thing for me would be music - stick on some of your favourite tunes. I get totally into it & sing my absolute lungs out & probably get lost/carried away with it - but it serves a purpose i that it uplifts me & helps clear any negative feelings, by the time I'm finished singing like a twat those feelings have dispersed & i don't feel so bad about whatever it was.

I've tried meditation when I'm really, really in a shit mood, but admittedly when the red mist or storm clouds are over head I just can't concentrate enough & clear my mind for it.