I like the built-in, floating shelves shown below. This room has a bit of an eclectic mix that works although I would have chosen a different rug and would either lose the door or paint the door and trim the same color as the shelves..
another modern version of floating shelves..
Extending the orange paint to the shelves gives this room a sharp look. Also, notice the hanging mirror on the shelves; a hanging mirror or picture is a common decorative detail that designers add..
Ladders are another decor element that is added when it can work aesthetically and functionally..
Decorating the back of the bookshelves either by adding a paint color or wallpaper is an inexpensive way to add a special interest to your room..