I do about the same to mid limb,but no circles. Then figure out what I need to drop from mid limb to the tip,depending on how snaky the stave is,I will make 3 inch lines across the limb if it is really snaky 2 inch lines and then free hand to the tip ,keeping the outer limb line running with the center line I have drawn. Works for me.
I have seen the stencils used before and looks like that should work good also.
While I am freehanding the outer lines I can see the longitudinal grain and make any little adjustments I need as I go along.
Pappy