Something I am starting to get into. Of course, any notebook really would do.
I have started a very small one to keep track of the things that make me happy and the things that inspire me. So that I may reread and remember, and then regain a sense of hope and appreciation for my present life and for my future. To respect my past for giving me these joys, but to not dwell on the previous pains that accompanied them. One of my attempts to be more positive, or to at least live a more rewarding life.
I think I will end up starting a commonplace book as well, just to keep track of the things I learn and encounter. I am wary of starting a journal... "diary" in one, as every one I have filled in the past I have subsequently torn to pieces. I tried writing a journal once without anyone else's names in it, so it couldn't be ruined for me. It didn't work. I used to keep a dream log as well, but the more you keep track of your dreams, the more of your dreams you remember. In number and detail. It got to the point it would take me hours just to write one, and I don't have time to do that. That one, however, I wish I hadn't shredded.
Listening to: WITTR - Astral Blood