Wear a respirator when sawing, grinding or filing this stuff. The dust is dangerous to your lungs. Don't let it get too hot when working, because it will burn. Don't work in the house, because it stinks as hell. Give it a fine finish. I use micromesh abrasives with up to 12000 (twelve thousand) grit to polish it. As a last step, wipe it with some boiled linseed oil to seal the pores, let harden and polish with a cotton cloth.
In my opinion this is still the best and most beautiful handle material of all if you have good quality stuff. It is natural. It polishes like ivory without the bad tendence of ivory to crack. It doesn't shrink or swell a lot. It get's a nice patina during long use. It is extremely wear resistant and doesn't break easily. Some knifemaker once said that nothing sells a knife faster than a nice stag handle. And he was right.
Achim