Osage Orange is rumered to make the best bow but that may be because it's also the hardest wood to use. I think the problem is you have to carve within just a few growth rings or it will splinter. jtobako has a good recipe. How you carve it will depend on the wood. I would recommend hickory because it's easy to find at the appropriate length plus hickory is very forgiving of knots. Find a tree and select a dry branch. Bend it and release. If it has a nice snap to it see what you can do with a larger branch. Debark a staff with a diameter of at least three inches and use that otherwise untouched surface as the back of the bow (the plane facing the target). Then carve away the rest of the staff until it bends uniformly. For longbow arrows you just need any plant that grows straight. Shortbow arrows are harder to make because shortbows don't have that rigid bit in the middle that sets the arrow in the center of the limb's thrust. That means the arrow has to curve around the bow's handle just the right amount. It gets complicated, and I don't have any experience to share on that.... As modern persons we have the advantage over our ancestors in knowing that bow making WILL work, if properly implemented. So just toy with it, wear safety glasses and yeld to any creaking.