This combination of a waistcoat and brown chinos is a fail-safe option when you need to look effortlessly classic in a flash. Complete this ensemble with dark brown leather work boots to inject an element of stylish nonchalance into your look. Keep this look in mind when warmer days are here, and rest assured, you'll save a lot of time brainstorming for what to wear on more than one morning. As a 30-something Millennial gentleman, you probably want to start dressing like an adult man. If that's the case, ensembles like this are a tested option.