I purchased tool steel in a half inch by half inch bar. The sharpening method is taken directly from instructions for sharpening bits to cut metal. The image below is one I downloaded from a metal working site. The only difference is that I do not round the nose at all, but rather try to have a pointed end which contacts the wood.
Once the tool is basically shaped on a grinder, sharpening is pretty easy. Picture one shows how to establish the "front cutting edge angle" and the "end clearance angle" as seen in the diagram above.
DISCLAIMER: Composite sharpening wheels are not designed for sharpening tools with the side of the wheel. Do this operation at your own risk!
Picture two show using the flat of the grinding wheel to create the "face" which is at the top of the tool when it is in the tool holder.
Next I touch up the "side clearance angle" in the picture below.