Filleting and Skinning always
I used to scale whole fish and never again. Filleting is much easier and if done correctly you get all of the flesh. Then I lay the fillet skin side down on a flat surface and with the knife flat next to the skin pull the skin to remove the skin and almost zero flesh.
I caught a nice sized crappie in the river earlier this spring and it was tasty!!!! Spotted bass are tasty too. My favorite fresh water fish is Walleye. Blue gill are probably my least favorite but even they are OK. Hand sized bluegill fillets are fine. But smaller bluegill are too much trouble for a little flesh. Catfish seem to depend upon the water. From clean water a flathead catfish is hard to beat. Even channels and blues are good from clean water.
Fishermen need to be aware of the water where they are fishing. Some waters need fish to be removed!!!! Too many fish results in small stunted fish. A friend has a pond and lets me fish with the only requirement that I keep every bluegill!!! His pond has great bluegill all big and fat because he keeps them thinned out. I agree that some waters are overfished and catch and release is a good policy. But in lightly fished waters removing fish is not a bad thing. Ideally you release the really big fish and keep the smaller fish. The big fish eat a lot of forage fish and keep the ecosystem healthy. Also a large female produces a lot more eggs than a smaller fish. In short a given body of water can support so many pounds of fish. Too many fish and they are smaller. When you catch and eat a fish you make additional food availble for the remaining fish to eat and grow larger. Without large fish smaller fish take over and you have a lake full of small stunted fish. http://www.kentuckygameandfish.com/fishing/bass-fishing/KY_0508_02/index.html