A navy crew-neck t-shirt and burgundy chinos are the kind of a fail-safe casual combination that you need when you have no time. Tap into some Idris Elba stylishness and smarten up your outfit with black leather derby shoes. So if it's a boiling hot summer day and you want to look seriously stylish without putting in too much work, this getup will do the job in no time flat. Semi-formal outfits for stylish adults aren't actually that hard.