with our big hunter horses we use gymnastic exercises to help them learn to tuck their legs and have better form over the fences. I don't jump my minis but I suppose it would work for the minis as well. We usuall start with a ground rail set about 6-9 feet out from the fence to a vertical jump to another ground rail at the same distance as the first ground rail. You'd obviously need to figure out the distance required fro a mini in order for them to just take one stride before the fence. We then start adding more fences, maybe a bounce stride or a one stride or even a two stride, always ending with a ground line to go over. When we've done it a while we even get some gymnastics theat may be a ground line to acouple of bounces to a couple of one strides to a two stride and then a ground line. we always work up to it and start low on the height, even our jumpers usually don't do gymanstics over about three feet or so (these are big horse jumpers). This exercise works real well to teach a horse where his legs and feet are and really builds upt he muscles required for jumping. I figure you could do it with minis only thing is you'll be in good shape too, because you'll be doing a lot of running. Or another thought with the minis is to set up a chute or alley way withe jumps and teach your horse to free jump down them. I saw them doing it that way once at a stud farm in Germany with young horses that were not yet broke.
Just a couple of thoughts.
Carrie