The fork used for the drumstick grip is your typical straight branch with kick right/left depending on your grip. It is a narrow, pinch grip so it is shot straight wrist / fist, with forks cocked to the side.
Carve your pinch, something around 2" is about right. The center of the grip is high for the palm swell and then both sides fall off like a turtle shell.
Go small where your pinky lands and then carve whatever forks you like. The grip is longer in this picture as I always leave a handle while I carve and then cut the butt later in the build. -CD