I have the Snuffer tamer, and know a lot of folks like it, but for me the best way to get them super sharp is very simple:
1. The first time sharpening a head or after its been through a deer and into the ground, black the edges with a marker and then file until all the marker is gone - do no more than two or three strokes and rotate the head. Your edges should now be even.
2. Finish step 1 with just light pressure, rotating the head every stroke or two.
3. Then, what made a difference in how sharp I got my snuffers was the quality of the stones I used. Get the highest quality coarse, medium and fine stones you can find(I use the ones that came with my KME) and laying two blades on the stone at the time go through the coarse, medium and fine stones and you will be amazed at how sharp they will get and very easy to do.