When it comes to wood choices, strongly flavored woods such as alder and hickory are best suited to larger, more strongly flavored fish. Something milder, such as apple, cherry or maple, provides a more subtle, less formidable flavor. To get the best smoke production, preheat the smoker and the pan before adding the fish, skin side down. Then, brush a light coating of oil on the grates or spritz them with anti-stick cooking spray. Since most of the color and flavor development occurs as the fish is heating, it's best to burn a couple of pans of wood chips right off the bat rather than later.