You should remove about half an inch of radius for about six inches down. It isn't important that the result is perfectly smooth or consistant. The idea is simply to reduce weight and shield the user a little bit. Next, cut three peices of aluminum about six inches wide and long enough to wrap around the end you just worked on. I simply washed out a bunch of beer cans, cut them up and nailed them on with small nails.
Staples also work.
This peice shields the wood from the fire and makes the torch last a good deal longer. If you want, you can manufacture a shield disk out of aluminum to put on the flange to protect the rest of the torch. I didn't bother with this step and hence, the wood is a little charred part way down the shaft. Finally, wrap wick material over the aluminum and nail it down. Be sure it is fastened securely as nothing sucks so much as throwing flaming objects around your audience.