Find a nice, straight, 8 to 10 inch trunk somewhere around 6 ft long. Make sure you look at the bark before you decide on a tree. The bark of Osage has a criss-cross pattern to it, make sure it doesn't twist around the tree. Cut it down and take some shalac or wood glue and liberaly coat the ends of the trunk. As soon as you can, split it into staves, they will be wedge shaped, around 2-3 inches at the wide part.
After you split your staves, take a draw knife and remove the bark and sapwood, then shalac the back of the stave. If you have time, now would also be a good time to chase a ring, as it's easier than when it dries. If you chase a ring now, be sure to coat the back really, really well.