I'm really liking the monochrome look right now. Pieces paired together that aren't exactly the same color, but almost. It seems like it would take a certain degree of control. One of the parts should stand out, while the other should be a neutral in the same color family. This would keep it toned down enough, and keep you from looking like you're trying too hard.
(photos collected from sannatranlov.freshnet, anthropologie, and tumblr)