I journal. I began journaling after my T suggested it in our very first session. I was hooked and have kept up with it ever since. I keep an actual physical journal — not a journal online. I fill it with all kinds of things: my thoughts (of course), quotations, prayers, habit trackers, pictures, my bucket list, my life/therapy goals, instructions for relaxation exercises and meditation, coloring pages, affirmations/mantras, a self-care wheel, ideas for a 108-day mindfulness challenge, etc. My journal looks pretty and I love adding to it. It has been a tremendous help to me during difficult times. And, yes, I use it for writing letters too.