TOP TIP: Be sure to keep the litter tray right next to your bed, on the side that you sleep on, and never empty it.
Not only will you get a relaxing aroma while you sleep, there is also the bonus poosibility that you will step in it with bare feet, should you get up to use the bathroom during the night...
(If however you are like me and you just go IN your bed, then this won't happen, however you can still enjoy the smell)