It's always fun to mix and match colors and textures in search of a look that's unique but still coordinated. Many attempt this fabled fashion feat, but few are able to master it. There are a few things you want to keep in mind to make sure you're on the right end of the spectrum. First, your patterns should have a hierarchy; you don't want two kings fighting for the same crown. Make sure one pattern is slightly more pronounced than the other. In this particular outfit, the checkered pattern on the trousers stands out while the shirt's subtle stripes compliment the pants without vying for the spotlight. Second, contrasting patterns usually work best when they're in distinctive shades. Dark on dark can appear too matchy, but light stripes set against a darker plaid or herringbone looks effortless and balanced. And lastly, if you're new to mixing prints (or wearing them at all), keep scale in mind. Smaller patterns are generally easier to play with. As always there are exceptions to every rule, but keeping these tips in mind will help you gain some confidence in this tricky realm.
Outfit details and links below.