Soft metals can be sharpened quickly but they also dull quickly. A hard steel, like Damascus, is difficult to sharpen, but it holds its edge through weeks of use. Sharpening is a three stage deal, to do it right. Use a medium ( washita) or coarse stone to grind a fine beveled edge on the blade the entire length. Hold the blade so that you get the same angled bevel the whole length. Do this on both sides of the blade, so that the cutting edge remains dead center. ( You can change this for certain jobs, but this is for a working knife.) I like to hold the blade about 15-20 degrees up from the stone, on each side, so that I have a 30-40 degree bevel, depending on the shape of the blade, and what work I expect it to do. On thin blades, I may even go shallower on the angles.
Then the second stage is changing to a hard arkansas finishing stone, very hard, and raising up the blade so that the finishing angle is more abrupt. Again, depending on what blade I am sharpening, and what kind of work I am doing with it, will depend on how abrupt an angle I want. It may be 45 degrees for a knife I expect to cut saplings and wood for tools, tent pegs, etc, or down to 15 degrees if I am wanting to cut thin skinned animals or filet a fish, or shave.
The third stage, which is perhaps the most important, is to strop the edge on a leather belt, to remove the fine burrs from the edge, polish the edge on both sides, and straighten the thin edge so it stand in a straight line. The straightness of the edge determines to a very large extent how much drag you will feel using the knife to cut anything. The smoothness of the edge is also a factor. If you don't strop, the burrs catch and tear holes into the edge, and dull the edge quickly. Then you find yourself back with the stone, sharpening it again.
I put three separate bevels on one knife blade for a friend of mine, once, because he was wanting this knife to do a variety of camping chores. I put a coarse, 45 degree bevel close to the hilt for about an inch and a half because he was going to make temt pegs and fire tools with that part of the knife; The edge that lead around the curve of the blade, I made into a 25 degree edge, razor sharp, as he was going to use that part of the blade cutting fish, and fileting them. The point got a 25 degree bevel on both sides, because he told me he intended to use the point to open CANS! So, I made the point sharp, but strong, so he didn't break it opening metal cans. ( I did try to talk him into using a can opener, but He is old enough to be my father, and would not listen!)
And, I sharpened a knife blade that was going to be used exclusively as a patch cutter on a flintlock rifle, so I put a narrow bevel on one side, only, so that the other side of the blade would ride flush with the muzzle of his gunbarrel. If you think of how a chisel is shaped, that is how I sharpened his knife blade for that function. I don't think he has had to sharpen that knife since I did it for him, and he loves it. But, again, he doesn't use if for any pupose other than cutting patching.
