This casual street style pairing of a black crew-neck sweater and light blue jeans can only be described as outrageously dapper. If you need to effortlessly dress up this getup with one single item, why not complete your outfit with a pair of brown leather casual boots? When spring is in full effect, you'll appreciate how great this outfit is for transitional weather. Casual ensembles for 30-year-old men aren't actually that hard, as you can see.