Dave, I'll clamp the boo upside down, "belly side up", on a piece of padding like thin indoor/outdoor carpet. I'll start from the center of the handle and plane one limb, then reverse the bow and clamp it back down and do the other limb. I'll place the clamps on the end of the bow I am not planing at the time to hold it still and the weight of the planner will hold down the limb I am planning. I will still use the jointer to get the boo flat in the first place, but after the shape of the bow is cut out of the boo, it get's a little fragile to run across a jointer.
Diamondback, very sharp bow.