Collagen casings (sticks and 32mm) I tie with butcher twine.
Hog casings, I tie on the ends using the casings and then do the twisty
thing for my lengths.
I use hog rings on bulk sausage (bag) and Fiborous casings. (chubs and 3 lb'ers)
But I am new at this and I might be doing something wrong, but that is what I do.