type of wood, style you are wanting to make, what type of use you have inteneded for the bow,how many bows you have made(experience level) and where you live(availibility of materials) and this is just scratching the surface, dont let this be discouraging but informative. pyramid design is an all around efficient design, and it just grows from there. i like the holmegaard and mollgabet designs but i make alot of d bows, flat bows and one more factor, stave or board. hope this helps.enjoy the world of primitive archery.