Kept a general, day to day diary since early 2013, and a dream diary since late 2014/early 2015 or so (for my writing, having stolen the idea from a Mishima novel.)
If you're prone to anxiety or overthinking, I couldn't recommend a general daily diary more. No emo faggotry, just a general recording of your day, what you did, what you're going go do, how things went, etc. It's an incredibly effective exercise in order to 'write off' the day.
It's such a concrete pattern for me these days that I can't imagine just stopping it completely. It also has the added bonus of keeping my cursive fresh.
N. B. - make it handwritten, not typed. You lose a certain something once you're just cracking keys on a computer. The visceral aspect of putting pen to paper is much of the efficacy.