I agree with Kareen! I think it’s also a good idea to have an extra outfit to change into after if it’s hot out. And you wouldn’t carry this in your back most likely but extra tack if you have it! If something breaks (or your horse gets loose and breaks something) it’s helpful to have an extra bridle/stirrup leathers, etc.

Hello Eleanor, when I am at a show I have everything for my horse (saddle, bridle, saddle pad...) of course, my equipment (helmet, show jacket, boots...) and I carry with me a backpack with treats for my horse, a small bottle of water, lip balm, suntan if it's summer, a hoodie if it gets cold, a snack (banana, nuts, bars...), a lunge and I guess that's it!