This casually stylish ensemble is so simple: a cardigan and navy jeans. And if you wish to easily class up this getup with footwear, throw in derby shoes. In the colder months, when comfort is crucial, it can be easy to settle for a less-than-stylish ensemble in the name of convenience. But this ensemble is a stark illustration that you totally can stay cozy and remain stylish in the colder months. Surely a good choice if we're talking outfit ideas for over-40 gentlemen.