This classic and casual pairing of a navy double breasted blazer and navy jeans is very easy to pull together without a second thought, helping you look awesome and ready for anything without spending too much time digging through your closet. Finishing with double monks is a fail-safe way to bring a little classiness to your outfit. This ensemble is also ideal if you're on the lookout for warm weather wear to get through a tedious day. As a 30-year-old gent, you probably want to start dressing more elegantly. In this case, combinations like this are ideal as inspiration.