To remove the skin from salmon fillets, set the fillet on a cutting board, skin side down, with the tail facing you. Slide a flexible knife between the flesh and the skin on the tail end until you’ve separated about an inch of skin from the flesh. Grip the flap of skin between the thumb and forefinger of your left hand—use a kitchen towel if it’s slippery—and press down on the skin with a flexible knife held at a very small angle so that the knife is almost flat and flush against the skin. Pull on the skin with your left hand while moving it back and forth, side to side. Move the knife very slightly with your right hand to keep it flush with the skin but most of the movement should be made with the skin, not the knife. Keep pulling and moving back and forth until the whole skin just pulls off. Turn the fillet over to see if you’ve left any patches of skin attached. If you have, slide a sharp knife under the skin and remove the skin by sliding the knife under with the blade facing upward at a gentle angle so you don’t cut into flesh.