Having a sofa up against a wall isn't ideal. Most of my favorite interiors have freestanding sofas--it can make the seating area more intimate and actually enlarge the feeling of the room. I, however, live in a long, narrow apartment and don't have such luxuries. My sofa is parked against a wall and the area above it is a major focal point because my ceilings are ten feet. The wall runs through my living room, dining room and kitchen and has the potential to look very cluttered, that's why I'm going for the less is more approach.
I love the idea of creating a beautiful focal point with one fabulous large-scale piece instead of lots of little things. It's also a clean look that can really set the tone for the rest of the space. Getting the scale right can be difficult but I sternly believe that every room should have one oversized piece. My sofa is 6.5 feet (78") long so I picked up a 40"x30" canvas from Blick during their last sale. I could have gone bigger but given that I'm not a professional painter I didn't want to pay more for the larger canvas. The scale is (almost) right, now I just need to decide what to paint! I'm going to look to the rooms pictured above for inspiration.
So I must ask, what's above your sofa?