When majoring in Industrial Arts we were taught to sharpen tools on a wet wheel to produce a hollow edge. Once the hollow edge is produced you use a series of progressively fine wet (black) sand paper starting with about 500 and ending with 1000. These papers are mounted on a piece of glass to for a perfectly flat surface. The edge is conditioned by bringing the edge of the blade into the paper, not away. At the 1000 grit mark, if all goes well, the burr edge will begin to fall off (wear through). At this point head to your leather strop conditioned with fine rubbing compound. The burr will then be abraded through. A few more strokes and you will have a fabulous edge. You can buy a cheap wet wheel grinder unit at Harbor Freight. This technique is the same for lathe tools, knives, chisels, axes, .....Although I find a single stroke (fine) file out in the field with an axe is an excellent way to sharpen an axe, lawnmower blades or yard tools. Pull the file across the face rather than taking full stokes at a 90 degree angle. Done this way a file can produce a raiser sharp edge on tool steel.