I think it depends on the recipe. I do know though that theres Cold Smoking and Hot Smoking. Hot Smoking has added heat during smoking to cook the fish too, like the mackerel. Cold smoke is lower temp but usually the fish has been cured already so can already be eaten. Kinda like the Norwegian style smoked, still moist.
That being said. Ive never smoked myself, just what Ive learned. If I had a house I would definetly try.
We smoked a steelhead on Dec 24. Fillet the fish with the skin on. Smoked for 2 hours on a Weber Smokey Mountain. We used bricketts and apple wood. A little sprinkle of salt at the end. Turned out very good. I helps when you have a 95 year old that has been smoking fish for a least 60 years guiding you through the process.