I have made fishhooks from bone and arrowheads from Antler. If you are going to make something from bone it needs to be raw bone otherwise it will have grease spots and may be weaker than raw bone. The only "flat" bone that you can get is a cows leg bone. They have one bone that is triangle shape in cross section. You can several flat pieces of bone from one of these. The bone needs to be cut open at the ends, the marrow taken out and then cleaned and dried. You can leave the bone out in the sun or bleach it, to get that white look. If you use cooked bone you will get a gray spotty color. You will need to find a good butcher to talk to so you can get the correct bone.
Antler is a bit easier to work with since it is already white and you don't have to clean it. It does take a sharp edge. The arrowheads that I have made I have not shot into anything for fear that it would pull off when I retrieved the arrow. I made my antler arrow heads large with a hole drilled for the shaft, instead of flat like a steel head.