As you can see, it doesn't require that much effort for a man to look on-trend. Just wear a navy plaid wool blazer and navy chinos and you'll look incredibly stylish. Ramp up the style factor of this getup by slipping into navy leather derby shoes. Is there a nicer option for a boiling hot summer day? And if we're talking style tips for 30-year-old gents, this ensemble suits almost anyone.