What did we do before Google?
There was a...
*gulp
...before google?
*blinks incredulously
I used electrical tap and sharpie. 1 color tape, each, for Speakers/Interconnects, Ethernets, HDMIs...
I wrote crosswise on the tape and cut enough to loop around the cable and make a little tag; clipped off any sticky ends that were left behind. Not too obtrusive.
I used those plastic tags, once, that were basically a wire tie, like the handcuff/zip-strip stuff. Hated those. They caught on things as you were laying or pulling up cable.