Its fun, like coloring books
also I take pictures, schematics, and layouts, and fill in info on them
I should take more pictures with a camera and then map on them, since it would reduce flipping back and forth between top/bottom of circuits. 1 Serious problem with that is, like on a big PCB that flexes under its own weight when held and turn up/down/etc. I am worrying about my oscilloscope's PSU board I'm working on, it want to rest in a nice comfy box
i am using a fine tip markers and marking up a few PCBs i have, morfe to follow
if for any reason someone else acquires them, i will have saved them much time