Infuse a relaxed vibe into your current rotation with a white and navy horizontal striped long sleeve t-shirt and sports shorts. And if you want to effortlessly play down your outfit with footwear, why not complement this getup with a pair of black sandals? Come roasting hot sunny days you're looking for an outfit to keep you cool and dapper –– this outfit is just the right one. Guys who wonder how to sport cool casual outfits as you go through your 20s, this combo should answer your question.