Some wood is easy to split.  Osage Orange is NOT.  It is important to begin the split through the pith of the wood.  I make sure the split is centered by making a shallow saw cut in the end of a stave to set the froe.  Wedges are used to keep the split open while working the froe down the stave.  I generally only need one wedge but two is good to speed up the process. 

This photo shows a common problem with Osage Orange.  The grain twists from end to end.  This will have to be a consideration when laying out the bow. 

The bark and new wood is removed until a suitably thick growth ring is reached. 

This close-up shows the wood in the growth ring as well as the honeycomb-like vesicular layer between growth rings.  These function as a good marker while shaving down to single ring.

Sighting sown the stave is very important while making the bow.  This one has very little twist but some distinct curve.  Sighting along the stave is far more accurate than trying to create a line using other methods. 

The above photo shows the growth rings as the stave is shaved to a single ring. 

A finished self-bow will often show the eccentricities of the wood which makes it all the more beautiful to those with a discerning eye.