I recently started reading a book about bombproofing your horse, and as I was reminded of the psychology of it, I had an epiphany; I could apply the same ideas to make myself a braver rider.
Basically, in working on de-spooking or bomb proofing your horse, you are gradually making them confront a scary thing, first from a safe distance, then gradually increasing the pressure until it's no big deal.
So it occurred to me, if I am worried about my horse spooking, or even trying to turn and bolt on me, I need to set up a situation where my horse is nervous, but I can handle it and bring him back under control.