I think I have shown locally at about every type of show that allows minis! I started with local shows, where you can always do halter and showmanship. If you ask - we did one year- maybe you can get others interested and add some mini classes. The judge might need help, but we wrote out rules and everyone had a great time, including the judge!
Our first love for shows is Pinto shows, which is why we breed for pintos. Can't say enough about the fun, the awards, the varied classes, the fun, etc....
We drive, so we have done American Driving Society events and non-sanctioned ADS-type shows. Do you see a pattern here? We like to show where there are BIG horses too! Don't need registered minis either.
We have also shown AMHR and AMHA because we do have those shows in our area.
ETA: Forgot that with our new 4-H Club the 4-Hers will be taking some of our minis to the County 4-H Fair as their projects.