Stan, I make 2 adjustments and grinds. One for the heel and one for the toe. I use a Jet 12in disc with a quality 120 PSA disc. Final fit and polish is done by hand with a sanding block. Like many things in gunsmithing it is not the only way to do it and others get good results with other methods but this is what works for me.

https://www.youtube.com/watch?v=BiUwiXb1Bss