This pairing of a navy blazer and blue jeans comes in useful when you need to look on-trend in a flash. Want to go easy when it comes to footwear? Complete this outfit with a pair of white canvas low top sneakers for the day. Needless to say, it's easier to work through a summertime afternoon in a easy and breezy combination like this. This combo is most probably exactly what you've been looking for as a gentleman in his 40s.