There are, however, tricks to animating capes, or other flowing garments.
Consider them fluid. Motion creates ripples, starting at the source, and radiating outwards.
Meaning, for a cape to flow in the wind, frame one, the first bone should be the only one animated, then the second in the next frame, and so on. After that, just adjust it 'til it looks natural.
Be sure to check it from all angles though.