I have a mix of original art and prints on neutral walls, less is more. I also like 'leaning' artwork against a wall either at floor level or on a shelf (along with ornaments, photos etc). This has the advantage that they can be easily moved around until the 'right' place is found. The frame is important too as the wrong frame can spoil good artwork. I would never buy any original artwork online without seeing it first in person, even a litho print can look very different online. Also with some artwork it's just as much about the texture and even the smell of the materials used, which you can never appreciate from an online image...