You forgot that you should also get the inspection lamp nicely warmed up and then press the hot shroud against your arm, to save doing that later. Also smash your head against something solid rather than battering it on the underside of the car when your arm makes contact with the hot inspection lamp.

It's also worth putting your thumb on the workbench and smacking it with a hammer before starting. It's so much more difficult to get a good swing at it while under the car and it often takes several swipes, hitting other things, before getting a good solid thump on the thumb.

If changing brake discs, remember to drop one on your foot before starting.