For a look that's refined and totally camera-worthy, rock a navy suit with a grey sweater vest. You know how to dial it down: tobacco leather derby shoes. This combo is an obvious choice when it comes to a killer summer-to-fall ensemble. As you're transitioning from your 20s to your 30s, you probably want to start dressing in a sleeker manner. In this case, outfits like this are ideal as inspo.