When the situation allows an off-duty menswear style, try teaming a navy denim shirt with navy jeans. Introduce brown leather derby shoes to the equation to immediately bump up the fashion factor of this ensemble. As you can see, it's super easy to look stylish and stay snug when chillier days are here, all thanks to combos like this. Modern and age-appropriate for a 20-year-old gent, a look like this will help outdo any of your peers.