Without seeing the space, it's quite difficult to provide a layout, although it needs to be multipurpose so the furniture should also be. For example a sofa bed or I like the idea of a loft bunk with a desk below, they often have bookshelves in the ends, or you could have that built. They can be costly, but the more you build in one unit the cheaper overall. Perhaps these two items together so the room can provide a work space, child's sleepover, sofa for relaxing and a guest bed, all in o e space.
Just keep things looking simple, and storage storage storage. Good luck.
ML Design

Old post from July 2013