I'm always worried about the seal being "food safe" and I have also heard that the wax can alter the flavor slightly, so for the mugs that I have made, I've been using plastic inserts from used frosting containers. They are just about the right size and you can put coffee in it without altering the flavor. I just make a koozie (sp?) with a handle. (make sure that you punch a large hole or series of holes in the base if you plan to remove the plastic to wash) I would suggest this as a good starting point for inexperienced persons who would like to try to make a mug. Also, it's an excuse to have cake!
I wish I had pictures of a finished mug, but I gave them out as Christmas presents.
Anyway, Great tutorial. I have been meaning to try it, but I have been too chicken to get started. I'll give it a shot.