A pea coat and a black crew-neck sweater are a combination that every sharp gent should have in his closet. Black leather slip-on sneakers are an effective way to inject a dash of stylish nonchalance into your outfit. So if you're searching for an ensemble that's dapper but also totally spring-appropriate, this one fits the task well. So as you can see, in your 30s you have a wide array of styling options.