A navy blazer and a light blue chambray dress shirt are indispensable players in any gentleman's sartorial collection. To infuse an air of stylish nonchalance into your look, slip into tan suede driving shoes. You're guaranteed to always look stylish even despite the oppressive heat if you keep this outfit as a last-minute grab. When it comes to outfit ideas for 40-year-old gents, this getup looks nice on almost any gent.