yes the kiss principle is the way with rainbows. Don't overcook. Fillet larger fish >14 in fry smaller fish just headed and gutted - scaled too if you like to eat the skin. Roll in pancake mix, bisquick, whatever, a little salt pepper, maybe lemon pepper, or Lowry's Seasoning salt. Fry quickly in light oil, butter, or a touch of bacon grease. Fish is done when flesh just flakes.
Wrap headed and gutted fish in heavy duty foil after putting a pat of butter and moderate shake of Lowry's seasoning salt. Place right in the fire or on good coals for about 15 min depending on fire and size of fish. Better not to over do it. Tastes great on the lake or river bank.
KISS = keep it simple silly