Old School: Mixing patterns and prints makes you look clownish.

New Rule: Mixing prints is a great idea—the look is unexpected and sophisticated. Just make sure the patterns are in the same color family or have a color in common. And the scale of the prints should be balanced: If you wear a larger print on top, wear a smaller pattern on the bottom, and vice versa.
Shirt, $13; OldNavy.com
Skirt, Nicole by Nicole Miller, $44; JCPenney.com