Something I learnt in therapy and found useful was the PACE activity - writing a list of things that support my wellbeing, divided in the categories of 'Physical' (movement, body care, etc.), 'Achievement' (things I can achieve, no matter how small), 'Connection' (i.e. social), and 'Enjoyment' (eg. interests, pleasure, relaxation). When I'm looking for ways to improve my mood or care for myself, I can turn to this list and reflect on what areas I may need to focus on more, as well as get ideas for things I can engage in. I find this particularly useful when my emotions are heightened and I'm struggling to think of what I could do to help myself feel better. 

I've worked hard to think of lots of things to add to my list, and just some of my options include:  jigsaw puzzles, taking a bath, visiting the library, participating in forums, doing stretches, listening to music, and planning my reading list.