Wash fish using fresh tap water. Cleaning fish in lake or stream water can sometimes contain contaminants.

Remove scales by scraping the fish with a fish scaler or the dull edge of a knife. Starting at the tail and going towards the head, use small strokes. This step will not be necessary if you plan to skin the fish before cooking.   

At the belly of the fish, make a cut from the gills to the vent.   

Remove the guts with your fingers. Check cavity carefully making sure everything has been removed and rinse the cavity well.   

When cooking a fish whole, the dorsal fin should be removed by cutting along each side of it and carefully pulling the fin out with pliers.

Wash the fish inside and out with cold, fresh water. Store the fish covered with clean ice in a container that it can drain from as it melts.

To skin a raw fillet place it on a cutting board with the skin against the board. Check for remaining bones. Cut any remaining bones away or pull them out with needle-nose pliers or tweezers, do this while the skin is still attached.

For a better grip, use a little coarse salt on your fingers or use a paper towel.

Start at bottom by tail; cut through fillet to skin, and turn the knife so blade is flat. The knife should now be located between the skin and the flesh. See photo I

Angle the knife down slightly so the edge points toward the skin. This ensures that you cut only the skin away and a bit flesh. See photo II

While holding the skin tightly, carefully slide the knife all the way down the fillet. Use a gentle back and forth sawing motion. This will enable you to cut all of the flesh from the skin. See photo III

To skin a cooked fillet: Grab the skin at the tail end with tongs as soon as the fish is done; the skin of most fish will easily peel away once cooked.

Clean fish as soon as possible after it comes out of the water.

When storing cleaned fish on ice, don't allow melted water to touch the fish. As the ice melts drain or discard the excess water.

Do not let water pool in the cavity of a fish. To eliminate this from happening store the fish with the cavity facing down.

Don't trim the fins before removing them, because bones at the base of the fins could be left inside the fish.

Choose a knife with a long, flexible, sharp blade. Be very careful when using sharp knifes.

Scale the fish when it is raw, even if you're planning to remove the skin after you cook the fillet, Scales will fall off during cooking and seem to always find their way into your finished dish