If they are cut too thin they are very dry. The location of the net will affect the quality of fish. Fish caught early in the season will be in better shape than those caught at the end. Salmon from one side of the river might be in good shape. Salmon from the other side might be about to spawn in a nearby tributary.
Some people smoke with cottonwood.
Some use birch. Others use alder. Some don't smoke them at all. Some people soak their fish in salt brine before hanging them. Some use sugar.