Focus on yourself, your goals, your horse, not showing or jumping higher that the other girls. Relax, focus, know yourself, know your horse!
Wow it is a wide question aha, it depends a lot on your discipline, your level, your flaws...
I would say to never give up, to work again and again until you reach your goal.
Above all respect your horse and think about every action you have on the saddle (how does it affect my horse, am I sure I give the right message, why isn't it working...)
For a more technical aspect, keep your eyes far and don't look at the ground 😉