Shelving, whether wall-mounted or freestanding, creates a dramatic backdrop behind the sofa. In the middle of a room, you can use open shelving to divide a space and anchor your couch. (This photo is from our old apartment. We've since given away the shelves, but this arrangement served us well for a long time.)
This sweet steup is from Design Sponge's Sneak Peak of Tonya and Mike Sutfin. They created a breakfast nook behind their couch using a folding table and a couple of chairs.