I find that the most important thing in this equation is not how to cook it, but how to cook it in a way that doesn't create smelly fish garbage. This will help GREATLY reduce the likelihood of you coming into contact with a bear that can and will smell your fishy garbage...
Any method using foil or wrap, bags or pouches that get thrown out or make contact with fish are, IMHO, useless in the backcountry.
If fires are allowed where you are camping, I recommend the stick method. Gut your fish, create a bed of coals, and just insert the stick into the head, with the remaining lower part of the fish hanging over the stick, tail at the bottom. Soaking your stick in water for a while, or simply taking one that has been submerged in the stream you fish would be ideal to reduce the risk of burning.
No prep work is required other than gutting the fish. You can burn the skin (if you don't eat it) and the skeleton and stick in the fire to help with no smelly leftovers for the bears.
I also like the simple method of putting a little bit of water, olive oil and salt/herbs into your normal backpacking pot or pan and just steaming it. Fish cooks in just a few minutes, its really easy. You can drink the remaining liquid or just pour it over rice.