Day As An Equestrian Rider
My ideal horse party would be a whole day as an equestrian rider - you could do it with hobby horses. Each party guest would get to pick their horse or make their hobby horse out of paper or old socks. Next you would get to care for your hobby horse.
After that you ride out(in a nearby football field, woods, or beach) after that you would practice dressage, show jumping and cross country.
When you have finished practicing the competition will start. If you want to you can have Pony club Games in party too!The winner will get a trophy(made out of a wineglass with paper handles at the side) and a red rosette (made out of crepe paper and coloured paper). Other participants will get rossettes and mini prizes like horse stickers,stamps and pencils etc.
After that you may care for your horse or ride out again!!! If you would like to you could make the party into a sleepover and do a two-day-event(just like the real three-day-event with real horses!!!)
In the evening you could relax and watch a movie and make or organise a stable for your hobby horses. In the morning(if you had a sleepover or two day event) you'll be able to get up early and feed and groom your horse, just like the real thing!!! then the second day of competition will start. (I couldn't find any photo's sorry!!!!! They weren't saved onto this computer!)