Just remember to follow what was mentioned earlier about not trying to split clear through until your split line is established. That's another reason I keep 2 sharp axes available. If your split starts leaning, you can reestablish to your pencil mark with a good tap on your axe from the split to where you want to take it.
I've been talking to Eric Bartels (rockcityusa) on Ebay and invited him to check out Primitive Archer. I get most all of my osage from him or his dad because I can't find any close to home to cut. I'm going to have to pick his brain and find out his method because he and Lavern have some of the cleanest split wood I've ever gotten.
Eric mentioned he'd like to try his hand at making a selfbow and I told him he'd get much better directions here than he could from me.