One of the reasons that I shoot longbows from blanks is that I know I will be changing the grip anyway. I have adjusted the grip on all but three of the bows that I have owned over the years. I start with a new combo wood rasp, then 60 grit cutting sand paper, then progessively lighter. Remember that once the grip is the right size and shape, stop gripping it. The oil from your hands can fight with the finish. I use satin Minwax to reseal and tape off the rest of the bow to prevent over spray. One kinda needs to watch the that the grip does not try to move the center of the bow up or down.