I had a horse that really didn't want to go off by herself.
I tried the treat at the end of the trail thing. As soon as we got as far as I was planning to ride, I would get off and give her a treat. It seemed like a wonderful idea; however, it really didn't work that well. She kept on refusing. I never did get that horse to do all that great at riding off by herself. She was so gentle that I ended up using her for my "company" horse. She would follow my other horse anywhere. She just hated to lead the way.