Always pack a quality flat sheet and a pillow case in a Ziploc bag. Mine is king sized. It takes up almost no room in your BOB and you will be much more comfortable.
The sheet will keep you much warmer then just a blanket, it will be softer and the bag will make sure it is dry. It also works as a screen for getting dressed and undressed. The bag can be slightly inflated, put inside the pillow case and used as either a cushion or pillow.
Very useful hints.
Thanks!