A long sleeve shirt and dark brown skinny jeans are veritable must-haves if you're putting together a casual wardrobe that matches up to the highest style standards. Complete this look with dark brown leather casual boots to immediately kick up the classy factor of your look. As you can see, this look is a really smart pick, especially for transitional weather, when the temperature is getting lower. Now that's a look any 30-year-old gent will appreciate.