1. If the fish is still alive at the time of cleaning, dispatch it quickly and humanely with a sharp whack on the head, or by shoving your knife tip through its brain. The brain is located behind the top of the eye sockets, as shown here. Keep your free hand out of the way, in case your knife blade slips.
2. Make a shallow diagonal cut behind the pectoral fin, angling forward over the head.
3. Using the tip of the knife, make a slit from the end of your previous cut, alongside the dorsal fin, working toward the rear of the fish.
4. When you reach a point directly above the vent (forward edge of the anal fin), push the tip of the knife straight down through the belly.
5. With a light sawing motion, follow the spine of the fish as closely as possible, cutting toward the rear of the fish. Your knife should exit the fish just in front of the tail.
6. With the tip of your knife, enlarge the slit you made previously along the dorsal fin. Follow the skeletal structure closely to avoid waste, and slice gently until you reach the top of the rib cage.
7. Carefully using your knife tip – or just pulling with your fingers as shown – work the filet over the tiny pectoral bones and ribs.
8. Now cut the filet free from the fish, getting as much of the soft belly meat as possible.
9. With your finger tip, feel the filet above the front of the ribcage. If you were hasty, you may have trapped small pectoral bones in the filet. These are easily removed by cutting a small wedge out of the filet as shown.
10. Beginning at the tail end of the filet, slice through the meat to the skin, but not through the skin. In a sawing motion, slide the knife forward, parallel with the table, as you hold the skin stationary with your free hand. This will separate the filet from the skin.
11. Wash the filets under running water and pat dry with paper towels.
You may encounter small parasites in the flesh of panfish. Small black mites look like grains of pepper in the filet. I generally leave these alone, since they are destroyed by cooking, anyway. Small cream-colored grubs would also be destroyed by cooking, but their presence appears more objectionable to me. I remove them with my knife tip during the washing procedure.