The key to crispy fish skin is to pat dry the skin of the fish then scrape the skin with a knife to get the rest of the moisture out. Set it aside and work on the other filets. When you're ready to fry, preheat your stainless skillet on medium then add the oil/butter and the fish skin side down first. Only flip once and never move the fish around until it's ready to flip. Depending on the thickness of your filet and temperature of your burner cooking times may vary. Remember it's very easy to overcook fish.