I use a Work Sharp guided bench and a Work Sharp power sharpener to establish the primary bevel. Usually this is 17 degrees and established first with a coarse belt or coarse diamond plate. Once the bevel is ground all the way to the edge, removing any nicks/rolls, etc., the bevel gets polished with finer grits. This alone will create a razor edge but to maintain the razor edge I use a Syderco Sharpmaker or crock sticks set at 20 degrees. The edge can be resharpened many times at the twenty degrees until the bevel needs to be reestablished again. What exact system you use is not as important as getting the bevel correct then maintaining that edge with something a couple degrees steeper when resharpening. I use this method for everything from kitchen knives all the way up to custom hunting knives.