Busy off-duty days call for a pared down yet casually stylish getup, such as a white crew-neck t-shirt and navy cargo pants. Infuse a more relaxed finish into this outfit by rounding off with a pair of black canvas sandals. Naturally, it's easier to work through a warm hot weather day in a cool ensemble like this. Gents wondering how to wear modern off-duty outfits in your 20s, you have your answer.