Pair a grey crew-neck sweater with a white crew-neck t-shirt to put together a seriously dapper and modern-looking off-duty outfit. For extra fashion points, complete this look with a pair of black suede desert boots. Keep this combo in your front hall wardrobe when spring arrives, and rest assured, you'll save a lot of time getting ready on more than one occasion. When it comes to casual outfit ideas for older guys, this look looks cool on almost any gent.