Reach for a black duffle coat and black ripped jeans to put together an interesting and modern-looking laid-back ensemble. If you want to break out of the mold a little, introduce a pair of black studded leather derby shoes to the equation. As you can see here, this outfit is a really great pick, especially for transeasonal weather, when the mercury is falling. Those who are curious how to pull off cool casual outfits as you slip into your 30s, you have your answer.