Make sure u are relaxed and calm. Horses can sense when u are tensed and stuff. Before I get on to ride I talk to my horse. I tell her stuff like "today is going to be a good ride" and "after this good ride u can't have treats and a nice cold bath." While I'm riding I just think nothing bad is going to happen. My horses is a good horse and she won't do anything bad. Since my horse is a new mom and her baby is 2 months old she goes a little crazy sometimes. I just stop her when that happens. Get off and talk to her. I try to calm her down. All of these things work for me.
Don't think about the past. Remember that a horse can feel your emotions, so if you're nervous or afraid or not confident, chances are it'll transfer to him and he'll be nervous and afraid and tense. And when you go to do a jump and you aren't confident, your horse will refuse. I like to pretend that I'm a pro and I can't do anything wrong when I'm feeling nervous. I just pretend it's only me and my horse out there riding and that nobody's watching. I pretend that nothing can go wrong. I pretend that I'm super confident, even if the truth is that I'm not. For example, when I first started jumping, I was excited but a little nervous. As we approached the jump I began to lose confidence and my horse refused the jump. I knew it was my fault. The next time we went around I told myself I was very confident and we went over successfully:) hope these two very long comments helped lol
Tell yourself you and your horse can only go up from where you're at, even if you're in a great position or the worst position. Tell yourself you can do this and you know you can. One of my favorite quotes is, "I don't lose. I either win or learn something." And I think that is very true. Because if you do something wrong to make you "lose" somebody's gonna have to tell you how to fix it. Think that if today goes bad, tomorrow will be great. And today can only get better from here.
Don't think about what could happen. Live in the present and just be greatful for small things the horse does when you ask. Like "hey, he/she stopped when I asked and didn't take off. Yay" idk lol but I hope that makes sense 😂
Another thing, I would sing one of my favorite songs out loud so I could relax and get in a good mood during a ride.