This combination of a brown crew-neck t-shirt and dark brown chinos is put together and yet it's relaxed and ready for anything. Consider low top sneakers as the glue that pulls your outfit together. Like this idea for your styling rotation as an older gentleman?
Why not choose a brown crew-neck t-shirt and white chinos? As well as super comfortable, these items look nice paired together. The whole ensemble comes together if you add a pair of low top sneakers to the equation. Now that's how you keep it casual in the style department as an older gent.