I sometimes sweep the wood down from breech to muzzle: High at the breech, low in the center, come up a little at the muzzle. This helps create a visual sweeping forward motion.
In my little world, I believe that straight lines visually detract from the form of a gun (painting, drawing, etc). The gun is all about the form. The shape of the stock must be perfected before the carving begins. When you see a gun from across the room that calls out to you, it's not the carving, is it? It's the shape.
I keep several dead fish and birds around to make comparative anatomy studies. I study women for their form, cars, airplanes, ships, trees, too. These are harder to keep in a drawer.