Pair a navy gilet with light blue jeans to create a seriously dapper and modern-looking casual ensemble. The whole ensemble comes together brilliantly if you complement this outfit with a pair of desert boots. Keep this outfit in mind come spring, and rest assured, you'll save a lot of time getting dressed on more than one morning. And if we're talking casual style tips for 30-something Millennial gentlemen, this combination is a good look on most.