When I was younger I had episodes of sleep paralysis frequently. For years I didn't know what they were about. Over time, I taught myself to focus on moving just the index finger of my right hand. And once I could do that the paralysis would dissipate.

Now that I'm older I rarely have sleep paralysis episodes. I read, somewhere, that sleeping on one's back tends to encourage episodes of sleep paralysis. This may be part of the reason I don't have them anymore because I find I can't sleep on my back. I pretty-much always sleep on one side or the other & occasionally on my stomach.