As the weather gets cooler and layering comes more into play with your wardrobe choices, don't be afraid to mix and match prints. There are a few simple rules to apply to make sure you are doing it well and not, well, very badly...
First, be sure patterns are in the same color palate. This helps the patterns work well together and show purpose, rather than laziness. Here we've stuck with black and cream and paired a large houndstooth cardigan with a small striped boucle skirt and solid jacquard top.
Next, be sure patterns are of different size - make sure you have a large pattern with a smaller pattern to compliment each other and not create a dizzying affect -- like here with a large printed tee and smaller Aztec printed cardigan. The large print anchors the outfit while the smaller print adds detail, interest and color, without competing with the top underneath.
Use accessories to introduce other patterns. Pair a striped top with a floral scarf. Here we've used a brightly patterned scarf to enhance the green in this marbled sweater.
Introduce other patterns through textures, too. Take a sweater and mix with a printed skirt to bring out the colors and variations in both pieces.
Following these simple rules will ensure you're perfectly put together. Have fun with your pattern mixing -- just keep to the principals of pattern play and you'll layer like a pro!