Most builders keep a few "test" pieces of stock wood when building from a blank. They are a good way of seeing how a stain or finish will work on that piece of wood. Many times on a kit or precarved stock , you might not have any extra wood for testing. What I do is apply my stain inside the barrel channel in a small area , I can add more coats and test as needed , I also apply very small areas of finish as well . Once I get as close as I want , I use the same amount of coats on the stock. There are probably other ways that work . This is just a simple way that works. Nate