Wear a crew-neck t-shirt and yellow shorts if you want to look cool and casual without putting in too much effort. Inject a laid-back feel into your ensemble by rounding off with a pair of brown athletic shoes. So as you can see here, it's a neat, not to mention spring-appropriate, ensemble to have in your transeasonal rotation. Casual outfits for 30-something gents aren't actually that hard, as you can see.