Wear a blazer and grey cargo pants for a straightforward outfit that's also well-executed. Up the appeal of your getup by wearing dark brown suede tassel loafers. A look like this can make any 20-something gent look better than everyone else in the room.
This pairing of a blazer and grey cargo pants is extra versatile and provides instant cool. If not sure as to what to wear in the shoe department, stick to dark brown leather casual boots. As you're transitioning from your 20s to your 30s, you probably want to start dressing like an adult. If that's the case, outfits like this are perfect as inspo.