A light blue harrington jacket and a crew-neck t-shirt are absolute menswear staples if you're putting together a casual wardrobe that matches up to the highest fashion standards. Go ahead and add teal canvas high top sneakers to your ensemble for a more casual finish. On not-so-bone-chilling afternoons, you can wear a variation of this easy-to-transition ensemble and look absolutely amazing. So if you need style tips on how to dress as you go into your 30s, this pairing is a perfect example.