A navy blazer and blue skinny jeans are absolute menswear staples that will integrate nicely within your current fashion mix. Rounding off with brown suede chelsea boots is the most effective way to add a bit of fanciness to your outfit. During the colder months, when warmth is essential, it can be easy to settle for a less-than-stylish getup. However, this getup is a practical illustration that you can actually stay snug and remain equally stylish in the colder months. Those who are curious how to wear modern casual outfits as you get into your 30s, this combination should answer your question.