Little first aid kit, grooming supplies, little gear like polos, boots, crop, spurs ect. :)
I have my riding gear, treats, show essentials and a fist aid kit just in case something goes wrong.
My helmet, treats, show essentials
Wet wipes/baby wipes! They’re awesome and very handy to clean off some poop stains off your horse or quickly get rid of some dust off your tack, or just simply clean your hands. Can be used for many useful things :)