If you're looking for a relaxed casual but also stylish look, wear a black turtleneck and a blue plaid long sleeve shirt. Put a modern spin on your outfit by finishing with a pair of white canvas high top sneakers. Keep this outfit in mind come warmer days, and we promise you'll save a ton of time racking your brain for what to wear on more than one occasion. Men who wonder how to wear modern off-duty style in your 30s, you have your answer.