For a casually dapper outfit, try teaming a dark brown sweatshirt with sweatpants — these items fit really great together. For a more casual touch, why not grab a pair of orange athletic shoes? Casual combinations for 30-something guys aren't actually that hard, as you see.
Pair a dark brown sweatshirt with sweatpants if you're on a mission for a look idea for when you want to look laid-back and cool. White leather low top sneakers will pull your full outfit together. Perfect if you're scouting for some seriously inspiring casual style for 30-year-old guys.