I recently read about and began to implement this with my own son. The Sleep Fairy. I told him she's watching him while he sleeps and when he stays in his bed all night, he may find a little reward when he wakes up under his pillow. A quarter, a small prize, or a piece of candy. He almost looks forward to going to bed now, just so he can wake up. After about 2 weeks, she will write a letter to him, commending him on how good he's been doing and to let him know that she has to go and watch over some other little children who need her, to learn how to sleep in bed all night, but she will be checking in on him. The two weeks of sleeping in bed every night is enough time to build a habit and the Sleep fairy will drop in periodically with a litle treat, to reinforce the good behavior.