A beige trenchcoat and white chinos are absolute must-haves if you're piecing together a classy wardrobe that matches up to the highest sartorial standards. Complement this outfit with dark brown leather sandals to bring a sense of stylish nonchalance to this ensemble. This outfit is the definition of perfect for when temps are falling and autumn is in the air. Those who are curious how to wear modern casual outfits as you slip into your 30s, you have your answer.