Steaming fish is one of the lightest and healthiest ways of cooking fish. This method allows the fish to hold its natural flavors without losing most of its nutrients, and does not require any additional fat. It's suitable for most kinds of fish in any form, from steaks, fillets, or whole fish.

Steaming is a wet heat method of cooking. The food, or in this case, the fish, is cooked in a closed cooking vessel with just enough liquid to generate steam. The liquid is usually water, wine, beer, broth, stock, or a combination of those. Aromatics of herbs and spices can also be added to provide more flavor.
Have you ever steamed vegetables before? Well, steaming fish is pretty much the same for the method of cooking fish. If you don't have a steamer, you can still make do perfectly fine with what you may already have in your kitchen.
You can use metal canisters like small jalapeno cans, small olive cans, tuna cans, etc., to set the plate on. Just be sure to leave enough room around the edges of the plate to allow the steam to flow through.
Some woks come with racks and dome shaped lids. Some pot and pan sets come with pots that have matching strainer pots with them. The strainer pot can fit securely on top of another pot with the liquid holding inside that one. Place the fish inside the strainer pot and cover. Other possibilities can be a turkey roasting pot or a fish poacher.

Freshwater fish such as bass, catfish, and trout are a nice choice. More oily and flavorful fish like salmon really showcase their richness when steamed.
When plating, you can enhance the flavor a little by adding lemon, green onions, or ginger, with a splash of rice wine or dry sherry. Feel inspired to use what you like.
Have fun cooking fish and
good luck freshwater fishing! Enjoy