This pairing of a blazer and navy jeans is a safe option when you need to look seriously stylish in a flash. To give this ensemble a more laid-back finish, complement this ensemble with plimsolls. It's a savvy option when it comes to planning a killer look for summer-to-fall weather. As you head into your 30s, you want to start dressing more like a mature gentleman. That's when outfits like this come in very useful.