This isn't the first, nor will it be the last time I talk about mixing subtle patterns. I love the level of nuance involved in assembling a look that consists of multiple layers of complexity, yet appears simple at first glance.
Navy pants, blue shirt, blue jacket, green tie. This outfit seems (and really is) simple enough, yet each element is comprised of a different pattern/texture. Running through the photos below you'll notice the birdseye pattern on the jacket, the micro houndstooth on the shirt, the herringbone on the tie, and maybe (just maybe) the windowpane pattern on my trousers.
Now don't get me wrong, I enjoy overtly mixing patterns too, but for those of you who'd rather dip your toe into pattern play, this is certainly a safe way to do so.