Master casual style in a white v-neck t-shirt and blue plaid chinos. You can take a more refined approach with shoes and introduce a pair of derby shoes to the equation. As you can see here, as an older gentleman, you still have a wide range of outfit options.
This combination of a white v-neck t-shirt and blue jeans is hard proof that a straightforward off-duty outfit doesn't have to be boring. You can take a classic approach with shoes and slip into a pair of derby shoes. This pairing demonstrates that figuring out how to dress stylishly as you pass the big five-oh is quite manageable.