I am TRYING to tie a Henry's Lake Caddis as originated by Marvin Nolte and shown in Tying Emergers by Jim Schollmeyer and Ted Leeson on page 78. It calls for preening woodduck feather barbs backwards toward the bend, then pushing forward to create a bubble and tie off with a 6 inch tag end of the thread from the initial tie on using a couple of half hitches. How does one tie these half hitches without catching the bobbin thread? My success in trying to do this so far has been zilch, nadda, etc. All suggestions will be appreciated.