Pattern mixing can be fun, but it can turn into a hot mess if you don't stick to a few basic rules.
First, choose at least one common color to connect the two patterns. Here I took the easy route and used grey and black as common colors.
Choosing patterns that are relatively the same size is another hint. For example, large flowers paired with these small stripes would probably look unbalanced.
Shirt: Vero Moda
Skirt: Old Navy
Shoes: Le Chateau
Bracelet: Joe Fresh
Necklace: Forever 21
Have you had success with pattern mixing?