A white crew-neck t-shirt and a navy crew-neck t-shirt are the kind of a tested casual combination that you so desperately need when you have no extra time to pick out an outfit. To give your overall getup a smarter aesthetic, why not add black leather slip-on sneakers to the equation? This look is a viable option if you're planning a killer outfit for weird transition weather. A reliable option ensemble appropriate for 30-something Millennial gentlemen who like casual dressing.