I’m unapologetically anal about this 
I use a physical notebook that I spend a fair amount of cash on, cos I know doing so will make me take care of it and keep better track of it. Every time I sketch a track, I make a new page with general notes at the top (BPM, vibe, names of any scratch recordings) then at the bottom half of each page I draw one column for each instrument used so I can make specific notes on each (snap, patterns, volume levels, tweaks, progressions, etc.). That way I can come back to the sketch later and pick up where I left off.
Though I don’t do as much with electronic records, every month or so I’ll back up all my active projects/snaps and update this running list I keep of them on a Word doc. Any time I complete one I mark it as done, and write a few lines to remind me what’s on each bank. I save a copy of everything to a portable drive in case of crashes or theft, both of which I’ve experienced.
