I thought i put my technique on entering the astral. This is something my friend/teacher is showing me. You need an object that is hold dear and when you sleep imagine part of your soul anchored to the material world through your item. Then imagine the rest leaving your body but a string that pulls you back. For first timers you might not remeber what happened but your body will feel different for a while its your soul adjusting for leaving and going back. This is what i use but it requires practice but its easier as time goes on.
I hope you all take this information well.