To skin a salmon fillet: Place a fish fillet on a clean cutting board, skin side down. Starting at the tail end, slip the blade of a long, sharp knife between the fish flesh and the skin, holding the skin down firmly with your other hand. Gently push the blade along at a 30° angle, separating the fillet from the skin without cutting through either.
Fish on foil: Fish that flakes easily requires a delicate touch to flip on the grill. If you want to skip turning it over when grilling, measure a piece of foil large enough to hold the fish and coat it with cooking spray. Grill the fish on the foil (without turning) until it flakes easily and reaches an internal temperature of 145°F.