I kind of fumbled around through the years and came up with what Taylor does in his tutorial. Actuall once used its about as easy as purchasing them. Only difference is that I cut a lot of firewood and ahve a lot of round chain sharpening files laying around that get dull. I drill the ends of the slot like Taylor shows but then use a chisel made out of a file instead of a jewlers saw kind of like a graver. Even works on soft steel and requires less filing. Also make chisels of that nature to cut out the wood. Other than that I do it mostly like Taylor does but with a little less skill. His suggestions about when to grab a refreshment and of what type I can wholly agree with also.
DP