I've been going a bit crazy lately researching the era via plates, museum collections, paintings, and what-not. Metmuseum.org is an invaluable resource. Since I haven't got a clue as to what my dress will look like (aside from sheer, white and high waisted like most every dress from that time) I've decided to work out a mock up for a men's tail coat.
You can't really see all the wonderful tailoring on the blue coat on the left
(for a better look http://www.metmuseum.org/Collections/search-the-collections/80000817?rpp=20&pg=8&ft=men%27s+coat&when=A.D.+1800-1900&where=Europe&what=Costume&pos=156 )
I don't know how to describe the sleeves, but the come up higher than most shoulder seams. I think creating a more "rounded" looking shoulder, rather than the slightly gathered, more square shoulder on the green coat. There is a seam at the center back and one seam to each side which curves to the armscythe. The front panels come up, over the shoulder, the seam is placed on the back of the coat. The sleeves are quite fitted... how in the world do they get those huge poofy shirt sleeves in there? The pockets are actually more to the back, and as far as I've read they are functional. Many of these coats are not lined. I can't tell if there is a seam at the waist but I imagine one there would provide a better fit.
Anyway. I am a little nervous about the collar. It doesn't help that I can't decide on a shape or whether it should be a different, contrasting fabric like velvet. I believe this became more common towards the later 1810's. Metal buttons or self fabric covered one's? I need to go fiddle a bit.