Find a quiet, comfortable place (maybe your bed) and lie down in it as if you were going to sleep. If it's possible, close the curtains or make the room dark. Turn off your phone or anything else that could disturb you and set the timer for as long as you want to try this exercise (I'd suggest 20-60 minutes). Lie very still and let your thoughts wander, do not hold on to them or try to remember them, just let them pass by. If you feel like moving (still lying down), then do so. Let yourself go to the place of drowsiness; the half-awake, half-asleep state where thoughts start turning into dreams. When the timer goes off, record your daydreams however you'd like.