Like Abra already mentioned, try doing this later in the night.

Also, you may want to get out of bed for a few minutes and try to get your brain working again (Wake Back To Bed). It depends on how easily you can fall back to sleep.

Don't focus too much on attaining Sleep Paralysis. It doesn't really work that way. Instead, try to watch yourself as you fall asleep. Watch your thoughts turn into dreams as you hold onto a small piece of your awareness.