I'm a bit OCD about tack and grooming so I have a lot of pet peeves...
-Leaving the straps and girth loop on the saddle pad flapping around while you ride.
-Not tucking away the excess stirrup leather.
-Not using the keepers on your bridle.
-People who don't take the time to groom their horses before riding.
-When people don't hang the leadropes on the gate and let the horses trample them into the mud.
Intermediate Rider~Learning Equitation and English Pleasure~Interested in Eventing
A horse will tell you everything you need to know about him, if you listen.