I’ve been working on guitars for a long time and to this day I still make a schematic drawing of where all the wires go and how the switches and potentiometers are hooked up. I even make a tracing of a pickguard and as I remove the screws and hardware I push the screw in the proper location where they were removed from the instrument. It help keeps the parts from getting lost and it also keeps the different length screws from getting mixed up and put back in the wrong location.