I have two different models of Prince Racquets. Both are 3 size or 4 3/8s. One grip feels great the other feels less secure in my hand. I use the same overgrip on both. The handle that I don't like as much is almost round which makes it feel like it will twist easier. I would like to make the shape more oval or rectangular. So I;m thinking I need to somehow add something under the grip to make the handle slightly thicker in one direction. Anyone have ideas how to do this?