You can "Pessoa" them. It is a lunging apparatus that, when used properly, can greatly aid in developing a horse's top line, encourage them to use their back more, and increase flexibility.
For jumping, you put a fence in the circle when you're lunging him. Or you make him jump in liberty, or with a halter and you stay beside him (you have to run). I like to work on a line of cavalettis or of two fences with a certain number of strides to respect. You even jump with driving reins but I am not used to work with them.