Good old pen and paper! I keep a paper based day planner and a notebook with my ideas, thoughts, etc in it. Recently I have been also trying to keep track usin

Good old pen and paper! I keep a paper based day planner and a notebook with my ideas, thoughts, etc in it. Recently I have been also trying to keep track using an iPad Pro and Apple Pencil using an app called Nebo. I'm not ready to switch yet. (And for that matter I have never been able to switch in 40 years). Paper to me is long lasting. I can start something in a notebook, shelve it and then pick it up again. No need to update the OS or the app I used to create it (if it still exists).