Im trying to do that too i havnt got there yet so im no expert but from what i know about it the 3 biggest tips i can give you are

Awake back to bed-set your alarm 4-6 hours into your sleep wake up stay up for 30 mins-1 hour then go back to bed and then try

counting numbers in your head every time you exhale to help you relax

and....well....okay only two tips but like i said im no expert, aslong as you know not to move at all not to think to much and to ignore the rollover sighns it should happen just keep practicing

also ive got to ask someone els who knows better, isnt the tingling feeling the beggining of sp?