Listen to music before or when your riding
Thinking about as if its my personal training, a show is where you can test your skills to see where you stand and what you can, competing against others comes second
After I walk the course I don't speak to anyone besides my coach. I focus just on the horse and then I only think about on jump at the time. I let go everything.
Just remember that it's just supposed to be fun
Remember to breathe, and make sure your focused before you go into the ring
It just takes time going to lots of shows and finding out what works best for you, knowing your course and planning and knowing your jump of course of by heart by helps. Believe in yourself and trust in your horse. Before entering the ring clear you mind of any doubts you have and enter positively, if a single jump doesn't go the way you planned just keep going try not to let it affect the rest of your round. Breathe and keep calm.
Visualisation - I just go round and round the course in my head exactly how I would like to ride it.
Remember why you are there, and how hard you've trained. Trust your horse, and if you can't do that, don't go into the ring.