Fake architectural moulding on the cheap.
"A really great tip to add architectural detail to your space is through applied moulding," says designer Trish Johnston. "It's very simple and has a huge wow factor. Get your furniture first and then put the moulding on the wall. That way your lines and boxes aren't broken up by your furniture pieces. Then paint out the moulding the same colour as the wall." You can pick up wood trim like this for next to nothing at your local hardware store.