All I have is a cotton twist rope....would you suggest using a nylon, or a leather halter? Do you think it is really worth doing? Thanks!!
First off, you are going to be supervising the horse in a controlled area (not a big wide field) so he shouldn't get into a bind. Therefore you don't need to use a breakaway type halter, you can use any type. They won't pull so hard to break a halter anyway.
If the horse has already learned to yield to pressure (and he should before you go to this stage of training) he will step on the trailing lead rope and feel the pressure on his halter and stop. Then he will figure it out. You let him figure it out. He almost trains himself. You watch him so he doesn't get tangled or panic at all. It's a simple, "oh I felt a tug on my halter when I stepped on this trailing lead, I'd better stop and calmly step off it." A lot of older rope horses have this figured out and they don't panic at all. Teaches them to be calm, and figure out things, and sometimes even wait for you to help them.
As Westernspice mentioned, saves a lot of reins!