Along the lines of Getting Things Done, keep as much as you can (succinctly) in paper. In my case, I keep it in org files (Emacs Org Mode), with scheduled timel

Along the lines of Getting Things Done, keep as much as you can (succinctly) in paper. In my case, I keep it in org files (Emacs Org Mode), with scheduled timelines. You can then tell yourself that you have noted it down and will come back to it as per the planned timeline. Games that overwhelm your brain. This might sound counter-intuitive, but works fine for me. Bridge or Draughts problems, Math puzzles, programming side-projects etc. Music. Other mundane activities such as exercise, cooking, reading, sex (this one, may be not so mundane)...