My mare, Perky, is a 17 y/o NSH who is broke, broke, broke. Responsive, sweet, intelligent, and a joy to ride now that she's taught me how to cue her properly. She is, quite literally, perky.
The spookiness started when the horses stopped being turned out for the winter. The barn that I'm at prefers to use horse walkers (not something I agree with, but also not something that I can control). Perky's a naturally forward horse, so her excess energy turned into spookiness at sudden noises/certain areas, namely in the form of shying and small bolts. She's sensible enough that she calms right back down after her initial reaction, and I'm capable enough to stick to her.
The trouble with that is that I've started anticipating her spooks. I can feel myself tensing my back and waiting for her to react to something... she feels me tense, and gets tense herself; then she spooks more and more. It's a bad cycle. I loaned her out for an IHSA show this past weekend, and she did not spook once while all of the various riders were on her, suggesting that I'm a major cause. Oddly, I also appear to trust her far more on trails than in the arena. So, how do I get myself to relax and start to trust her again? I'm a decent enough rider, but I also tend to naturally be pretty nervous.