When I shave off my mustache, dark areas (hair roots?) And redness remain above the upper lip. How to get rid of all this?

You take a depilatory cream (girls use it often, because it is dangerous to wield a razor in that place) you rub your antennae, wait 3 minutes and wash it off)) voila! Your hairs went into conalization along with the root)

Use special shaving foam / regular liquid soap; when the main part is shaved, gently hold up a couple of times. The main thing is to do it carefully, because you can cut yourself and cause irritation.