I've been a writer and author for many years now, having been a precocious reader since early childhood. That experience, bound up with a love of literature formed the central core of my life. I was even present on the Big Wood River (Sun Valley/Ketchum, Idaho) when "Papa Hemingway" ended his 61-year-old life, at his cabin in 1961; we also had a cabin on that river, located a mere quarter mile upriver from his.
As an aspiring future writer, I was immensely impressed with Papa, whom we met daily while fly fishing along that river. Almost every other day in the summertime, he wore one of his favorite WW2 vintage khaki military shirts with big pockets and epaulettes...almost identical to that which you offer as your 'Nitty-Gritty Cotton Twill Shirt.' It never failed to give Hemingway that strongly masculine look that so complimented his adventurous image.
Years later, In Berkeley as an undergrad, I sourced out a supply of these shirts for my own use, puerily attempting to capture that same bold, spirit that so suited "Papa."
This style of double-pocketed, no-nonsense shirt compliments just about any adventurous spirit and I have acquired several of them in blue, khaki and OD to wear. They are tough and well-made, with perfectly functional pockets that "Papa" would highly approve of, and yet they're also VERY stylish, perfect casual male attire.
Finally, the price is also very reasonable, so I would recommend stocking up on a few before they are sold out! Another excellent product from 'The Territory Ahead.' The attached image is me, clad in one such shirt, while writing the next Great American Novel at a coffeehouse in Berkeley, in the early 70s. Great styles like this shirt NEVER go out of style!