Why not dress in a white and navy horizontal striped crew-neck t-shirt and dark green chinos? As well as totally comfortable, both of these pieces look great when married together. Rounding off with black leather desert boots is an effortless way to bring a sense of sophistication to this getup. This combination is a pretty savvy choice, especially for fall, when the temperature is getting lower. This ensemble shows that as a guy in his thirties, you have a wide array of outfit options.