So I guess I'm the odd man out because I leave the head and skin on, don't scale and I eat the skin! To prepare my trout I will take a sharp knife and make slices 90 degrees to the length of the fish and about 1/4" deep (more or less depending on the size of the fish). I do these slices about every 1/8-1/4" from gills to tail and on both sides. Then I will sprinkle on lemon juice, salt, pepper, garlic powder, and any other spices depending on how fancy I want to get. I also make sure that all of this is getting into every slice that I made. I heat up a pan with olive oil (2-5 table spoons depending on pan and fish size) and when the oil is good and hot in goes the fish. One of the keys to this is to only flip one time! This will take some practice to be able to tell when its time to flip but I'm sure you all have experience in the matter.
So, as the fish cooks the skin will become crispy and very tasty thanks to the slits. When it's done remove the fish from the pan but keep the heat on. Pour some lemon juice into the pan about the same amount as the oil. Stir this around scraping the pan as you go. The acid in the juice will dissolve the stuff that has stuck to the pan. When that has boiled down some you will then have a delicious glaze to drizzle over the fish. Pour yourself a glass of a good wheat beer and enjoy! If you do this, the skin will be one of your favorite parts!
I also do this with salmon and steelhead fillets but in that case I do scale them.