Some people are visual, others aural, and a minor portion kinesthetic. Meaning that we tend to learn and experience the world through sight, hearing, or feeling/moving. In order to reach them, we need to understand how to write in a way that touches all types of readers. Which Patricia C Wrede explains.
And, as a bonus: The Vickers Heavy Machine Gun
World War I. Trenches. Barbed wire. Machine Guns. Specifically, the Vickers Machine Gun. Which is an amazing piece of technology. If you want historical stories of the Vickers for your WWI books, just have a listen to Ian McCollum. My personal favorite is the firing of 5 000 000 rounds by a single Vickers gun. Firing a whole week, day and night, without stopping, and not a single breakdown.