Split some bone, deer in this case with a rock or etching and then breaking to get some workable pieces.
Using some rough stone such as sandstone, wet the surface and the bone shard. Start rubbing the bone on the rough surface and remove the imperfections and areas you do not want. Also thin it out so it has a uniform cross section.
After the piece is thinned out, start shaping it and give the end a pointed tip. Sharpen the sides by either grinding or using a stone flake to cut sharp edges. Saw serrations or notches with a modified flake with a serrated edge.
Here are 2 needles and one point. Old deer bone was used for these. Quick and dirty but very useful.
