The preformed grip is the easiest way. I have done it both ways. Glueing cork rings is quite time consuming. I you waterproof Elmers glue to glue them together. I have tried putting them on threaded rod, and turned the grip in a lathe, and in a drill press, but you will never get as good a looking handle as the preformed one. I have also mounted the rings dirrectly on the rod blank, chucked the blank in a latheput some tape on the blank about the size of the collet you have available, and put a live center in the bottom end of the rod blank, then turned, and sanded the blank to the desired shape, works good, but still the handle doesn't look as nice as the preformed grip. Just my dime.