There are a few methods. The easiest is with a 15 or 9 micron belt on a sander. I'm really just goofing off. Well, showing off. Some people just love to see mirror polished edges. It's really not necessary. In fact, a good 80 micron or 220 grit edge looks fine and seems to "bite" better when cutting. The polish will be roughed up the first time I do some serious chopping anyway.