You'll be surprised at how super easy it is for any gent to put together this effortlessly classic outfit. Just a waistcoat combined with white jeans. Break up this outfit with a more casual kind of footwear, like this pair of navy casual boots. If you feel uninspired by your transitional season style options, this look just might be the inspiration you need. Those who wonder how to wear smart casual style as you go through your 20s, this combination should answer your question.