Holding the blade with your left hand, place it at a shallow angle so that it is touching the middle of the top of the mushroom.
Turn your left hand toward you, while turning your right hand away from you, making sure that the blade is always in contact with the mushroom. It will automatically dig into the mushroom.
Place the blade back on the top of the mushroom, next to the first groove, and repeat the same movement.
You may need to adjust the angle of the knife in order to remove the skin, but not cut too deeply where the mushroom might break off.
After a cut, always lift the knife and replace it back at the top.
Continue around the mushroom. Don’t worry about the peelings that remain attached. They can be removed at the end.
If done correctly all the skin should be gone leaving a white, fluted cap.