This smart combination of a dark brown cardigan and a beige dress shirt can go in different directions depending on how you style it out. You can get a little creative with shoes and introduce dark brown leather casual boots to the mix. A knockout summer-to-fall look like this one makes it super easy to welcome the new season. In your thirties, you probably want to start dressing like a grown-up. In this case, combinations like this are perfect as inspo.