Okay, last night I was completely still in bed for the better part of 20 minutes, and I was trying really hard not to fall asleep. Trying to look at the imagery in my head wasn't working, and using the alphabet method (see Clairity's WILD tutorial) wasn't working, so I just took deeper breaths and made sure I could hear them a little bit, and that kept me awake. After a while, I suddenly heard a really loud ringing in my ears, almost like a high-pitched beep, and I couldn't feel anything. My hands were laying across my stomach and it felt as if they weren't even there. Then my body started... I dunno, trembling I guess, and I was taking really shallow breaths. I didn't even try to move in fear of 'waking my body up', so I'm not sure if I could move or not. It only lasted a few seconds, then I realized it must have been sleep paralysis and just knowing I'd gotten that much closer to lucid dreaming excited me... then I just woke up all together... and tried again. It happened again, but it wasn't as strong as the first one.

Thanks for the tips, guys! I think my problem was just staying conscious long enough and keeping my body completely still.