What I do all the time: take random pictures of little things that make me happy. Flowers, landscape, buildings, some funny things, fruit harvest, whatnot...

then i like to look at them to remind myself life is beautiful and wonderful.

I also have list of my tunes that help me get in the fighter mood. I paint my nails holo, cause... it makes me happy (and it helps in anxiety inducing situations, to just look at my sparkly nails to ground myself). I paint, draw and force myself to go out to events to make like minded people.