This smart casual combination of a navy and white horizontal striped crew-neck t-shirt and khaki dress pants is very easy to pull together without a second thought, helping you look awesome and prepared for anything without spending a ton of time combing through your wardrobe. Not sure how to finish your outfit? Finish off with a pair of black leather loafers to elevate it. As a guy in his 30s, you want to start dressing in a classier manner. If that's the case, getups like this are a life saver.