I find it specially interesting when it's done to "dissect" machines, making it look like schematics. I find it helps dispelling the impression of things being black boxes.
Use a big piece of cardboard. Screw screws into it in the same order they came out, and draw an outline of the part they came out of. Tape down small pieces that aren't screws. Label everything with Sharpie. It slows you down enough to prevent a lot of mistakes.
I find it specially interesting when it's done to "dissect" machines, making it look like schematics. I find it helps dispelling the impression of things being black boxes.