I made these dogwood wedges (or gluts) last week with a bow saw and hatchet. Dogwood is easily shaped with a sharp axe when "green", but is extremely tough to work once it has been dried. This toughness really make it good wedge material. We had to cut some trees down, and couple of the trees that had to be cut down were dogwoods. The trunks were cut into 18"-22" lengths and both ends were sharpened.
WIth both ends sharpened, the lengths were cut in half with a bow saw.
Then the tops were beveled to prevent splitting.
I have found that dogwood wedges are very durable, light weight, and can work as well as iron wedges. They can usually be made from "found" wood or trees that have been cut when clearing.
*And, of course, always use good technique and safety equipment.