This combo of a white and black horizontal striped crew-neck t-shirt and black chinos is proof that a pared down off-duty ensemble can still look really interesting. For something more on the off-duty end to complete your outfit, introduce a pair of black and white canvas high top sneakers to this outfit. This combination is an obvious pick when it comes to a neat summer-to-fall look. This getup demonstrates how to kill in casual dressing as a guy in his 20s.