I run the knife up the belly, cut the gills, run my finger along the back bone to bust the blood line and pull out the guts, grab the head and bend it back and peel it and the skin off all at once. I'll fillet the meat off after that. I've tried filleting with the skin still on and then skimming it afterwards but I can't get the hang of it. I've been doing it this way for years and I can fillet them as faster or faster than people who do it with the skin on and then skim it off after removing the fillet.