Im not sure of any that you can do with just one jump
, but one of my favorite exercises is 4 poles on a 20m circle - don't at a canter. You start out with one pole and practice getting a good spot to it and not splitting it [on front leg on each side, they need to take the pole in stride, just like a jump]. Once you can good at this then add a second pole opposite the first, and practice getting an even amount of strides on each half of the circle. Once you have mastered this, add the other 2 poles so the circle is split into quarters.
Also I like setting 2 poles in a 5 stride line [12ft strides with 6ft for landing and 6ft for take off] and practice getting 4-5-6-7 strides in the line. You can also do this with jumps