I have been working with a young horse on starting jumping. He is pretty wary of anything new, and very quick on his feet.
We started with a pole on the ground, until he could w/t/c over without leaping. Then two, three, four poles, raised poles, put the poles between standards and finally I had to bite the bullet and put up an x-rail.
Because I come from a dressage background, I train the horses that there is one place to go and that is right smack in the middle of my knees, on the line which I dictate. Speed and gait comes secondary. Putting a fence in the way does not change this. So I rode him to the fence and he did his best cutting horse impression trying to dodge out from either side and I just sat there riding straight until inevitably he stopped in front of the fence and then I again, just sat there. Eventually he got up the courage to get over the terrifying fence (all 6" of it) and thank goodness for mane.
The horse now comfortably jumps 2'6" lines, less than 6 months after the first introduction to poles, working at most once a week, more like one or two times a month. If you approach an exercise with confidence and a plan, and have prepared the horse for it adequately, training a horse is actually extremely easy. I take the same approach to trailer loading, and both my horses self load. Because the objective is clear, because it is made easy.
I fail to understand how a horse is supposed to get to go over a fence from circling beside it. Or to go into a trailer. A baby horse learns to cross a ditch because mom went over it first. Not because she endlessly circled beside it. Mom is not kicking baby to go over the ditch, mom is waiting patiently nickering on the other side of the ditch. This is how training should be approached, in a way natural to the horse, not natural to the human.
They say money doesn't buy happiness -- well happiness doesn't buy horses!