I pack a lot and just expect my horses to lead in a pack string. Its just never been a big deal to teach them to follow. Usually, I'm spending more time teaching them to stay in line and not try to pass. Occassionally they stop and refuse at a stream crossing and I have to use my saddle horn to offer a litte more encouragement to follow.
Never loop the rope around your hand, Allways be ready to drop it if the situation requires it. Same with using the horn. I never tie it off, Just a wrap and if needed, just let go and let it slip off.