maybe practise just getting to Sleep Paralysis, while your are quite mentally alert. ie before bed, the day after a good nights sleep where you havnt done too much thinking but have done some excersize in the day. if your mind is alert but your body is sleepy you might have more success?

binaural music, something with a slow bassy pulse to focus on, can be helpful to get to SP but i find it can stop your mind falling asleep to get WILD, but this could be helpful in your situation.

lie on ur back, head & arms nice and comfortable. DO NOT MOVE even to scratch. focus on something in the back of your mind, not with your "thoughts". give it plenty of time.

once you are well practiced at SP, you might then find it easier to fall asleep into a lucid if you try it after 6 hours sleep or so.