Marrying a brown waistcoat and charcoal jeans is a surefire way to breathe rugged refinement into your closet. And if you want to effortlessly perk up this ensemble with footwear, complete this ensemble with dark brown leather oxford shoes. So as you can see, it's very easy to look seriously stylish and stay warm come cooler days, all thanks to combinations like this. When it comes to style for 30-year-old guys, this look looks great on most men.