Maintaining a logbook by date. This enabled me to have some chance of reestablishing state when I knew the date of some action. It also collected all my scribble, notes and references in one place meaning I only had one thing to remember when wandering about. Eventually, two with my phone but they came way later. Yeah, it wasn’t searchable but no electronic alternative worked anywhere near as well nor were as robust when traveling. A good quality engineering spiral notebook..

This approach worked for all operating systems and languages that I used. Planning, work notes, summaries and speculations along with the everyday detritus that showed up.