For a foolproof relaxed casual option, you can't go wrong with this combination of a blue denim jacket and an olive plaid long sleeve shirt. Up the formality of this ensemble a bit with a pair of brown suede casual boots. It's a viable option if you're planning a standout outfit for summer-to-fall weather. This pairing shows that figuring out how to dress stylishly as you reach your 30s is easier than one might think.