I really enjoyed the feature in Real Simple on mixing florals with patterns; I think they nailed it when they said, "Mix them with colorful stripes, polka dots, and gingham checks in complementary tones." That really sums up the process, the key word being 'complementary'.

Many fear the process of mixing various patterns and prints in a room. Layering is actually quite painless. Grab a color wheel and a good book on color combinations, and/or take a color theory class at your local art school. Introducing yourself to new ideas via classroom instruction enhances your life in so many ways, especially in the cold months, it helps fight creative stagnation and feelings of depression. You'll also make new friends and tap into parts of yourself you never knew existed.

Of course, visual learning through the pages of your favorite magazines doesn't hurt, either. The more you expose yourself to beauty and good design, the more your brain starts to pull all the pieces together and you find your own creative voice, you develop your own 'eye' for style. I do believe that people are born with talent, but I also think developing a good eye can be trained if you're not one who was born with the ability to effortlessly throw things together to result in something pleasing. Try, try, try, again!

(images from real simple)