We also track what horses have been used and how much so that we're not riding them into the ground — the people on the ground have an app I built in Framework7 to manage everything; they love it and Framework7 is very fun once you get rolling.
We ask for a 20% deposit to "hold [your] horses" and to prevent no-shows; the rest is transacted at the ranch (though we make the option to pay in full available if you email us). Our cancellation policy extremely flexible and though we say 24 hours on the site, we've never not refunded someone.