Go over the course lots and give each jump a different 'name'. That seems to help me
At cross rails the corpses are usually simple and not hard to memorize
Walk the course at least 1 time. Then go over the course in your head repeating everything you learned from walking the course. Go over it over and over. Imagine yourself riding the course (that helps me best). But most of all give yourself PLENTY of time to learn the course. Literally when they post the course go try to learn it asap.
I will quickly half memorize it while looking at the paper then I will look out on the course and trace the path with my finger while saying a name that describes the jump. Then I walk the course counting the distances. After that I run around the course on foot jumping the jumps along the exact path I am going to take. Don't mind if people give you wired looks. It works.
Waking the course is very helpful! I also like to come up with nicknames for the different jumps and I just repeat the order that I need to go over them in my head. If you can I would also school your course. Going over the course with your trainer is also very helpful! Hope this helped you and good luck at your show😊
Walking the course is a must, but I also remember my course by closing my eyes and going through it in my head😊