Cut the leaves and branches off and loosely bundle them together. They will do what they're going to do as they dry. Wait until they turn brown or golden or whatever color you use to describe a dried cane - check the grove to see what color the old dead clums look like. Once they are dry you can sand or cut off any remaining vestiges of branches and start the straightening process. This is a good time to cut clums because the new ones are not up yet (well, maybe they are in your neck of the woods). Cut two year old clums so that they have had enough time to stiffen up. New clums will NOT make great arrows. Bamboo deposits silicon in it's cell walls as it ages and that's what makes it so tough. BECAUSE of that, DO NOT BREATH bamboo dust when sanding, USE A MASK OR if sanding by hand, use wet sand paper and keep the clum wet to keep the dust down. IF sanding on a machine, wear a mask and have your dust collection system working.