Well, it's sleep paralysis when you can no longer move your arms or anything. Of course, you don't want to be testing your ability to move arms when relaxing.

I consider the start of sleep paralysis when my breathing really tones down. My diaphragm only displaces a centimeter or two at the most. If I am not aware I am going into sleep paralysis, it will startle me because it feels like I can barely breathe.

HI tends to be really random and sporadic. It's not like it just turns on and stays on when attempting to WILD. It will turn on for a second, you see something happen quickly, and you may eventually drift into the scene. The thing that lets me know I'm the closest to a WILD are vibrations. The best way to get there is to take deep breaths and do not get lost on any trains of thought. Let them pass right through your brain.