What each kind of bow wood or composite materials are best for (tension, compression, durability, etc etc.) and designing a bow that maximizes their best qualities and minimizes their downsides.
Great example is hickory (add lots of other white woods to this like hard maple, ash, etc. etc.). Forgiving material and you can make many kinds of bow designs with it. But making it flatter/rectangular in cross section (as in a flatbow with or without a stiff handle/riser) to take advantage of its strength in tension and to minimize its less than exemplary compressive strength. Otherwise, if you try to make it into say, a heavy weight longbow/warbow with that kind of deep oval cross section, there's a high chance it will either take a ton of string follow/set or develop compression fractures/chrysals/frets (are those actually interchangeably the same thing or is there a distinction? would love to clarify!)
Osage and yew are better balanced between tension and compression, but have their challenges as well. Yew is well balanced, and does either an oval section or a flatbow design very well. Quality varies considerablyfrom stave to stave, and it requires a Lot of careful handling of knots, and since the wood is a little softer it's probably easy to take too much wood off by accident (please chime in people who have experience working with yew!!). Osage is less forgiving on the back than hickory, so you need to chase a ring Or back it so it won't fail in tension. But it's much better with compression so it can handle a fair variety of bow designs. It tends to be --from what I think I understand?-- to be most efficient at lower draw weights as some sort of a flatbow type of design though, as it was used historically and with traditional modern flatbows as well.
Context is important to consider in "design" as well. Are you trying to get your stick of wood to cast an arrow as quickly and efficiently as possible as far as fps and all that jazz? (I'm thinking more modern riser-shelf flatbows here?) Then you need to pick the best possible bow wood (or woods or composite materials if you're making a laminate) and choose a design that optimizes the bow's performance.
Are you trying to make an extremely accurate bow? Modern olympic recurves are designed, with modern materials, to shoot light arrows extremely accurately in extremely competitive contests to score points. Not saying they are better than traditional (that would be like blasphemy to say on this site!
) but they are definitely designed for a different context.
Or are you going for a bow that say, is a little easier to make in less time, and is durable for what you need it, even if it casts slower? Let's say a Cherokee style or a Sudbury designed hunting weight (45-60 lbs. or so) flatbow? Depending on how the bowyer makes it, Some Set/string follow, wider tips, slower cast, etc. is fine as the bow is designed primarily for durability in a moist hunting environment (so self bows would be both easier and more practical), ease of use, and definitely ease of manufacture (stone/bone/copper tools pre-Columbian exchange).
Those are my thoughts anyway. Anyone feel free to chime in, and any feedback to expand or correct what I've said is welcome constructively.