I fixed my right crossovers by dreaming about them once a few years ago. I had somehow gotten myself into a state where I could only do them if I was holding my coach's hand, even though I'd been able to do them on my own before. One night I had a dream where I was doing crossover after crossover after crossover perfectly, and woke up saying "oh yeah, I can do these things!" My next lesson, I told my coach she wasn't allowed to hold my hand, and managed them just fine on my own. (My right crossovers are still the skill most likely to go AWOL on bad days, but since I know I can do them I just keep trying until I get them.)