When the 6th edition for Warhammer Fantasy Battle came out, I started an Empire army. While I never played that army that much - somehow I never grew to like its gaming style - I put a lot of effort in painting it.
For a theme I chose the British army of the 17th and 18th century. One of my inspirations was the movie "The Patriot" (movies are always a great inspiration and a good way to get into the feel of an army).
While I did some research on uniforms, standards and such, the army is by no means "authentic". But I do think that it catches the style and feel of that time. While units, standards and musicians did not look exactly like I painted them, they could certainly have done so.