For a look that's pared-down but can be flaunted in a great deal of different ways, try teaming a light blue chambray long sleeve shirt with charcoal camouflage cargo pants. And if you want to immediately perk up your getup with one single item, add a pair of brown leather casual boots to your ensemble. Relaxed casual outfits for stylish 30-year-old gents aren't actually that hard, as you see here.