A navy gilet and blue print jeans are amazing menswear staples that will integrate nicely within your casual arsenal. If you want to immediately up the style ante of your look with shoes, why not introduce black leather casual boots to the equation? You see that just because it's cold outside doesn't mean your combos should get any less stylish. If you're wondering how you should dress as a 30-something Millennial guy, this pairing is a good source of inspiration.