My idea for these was to make modular sections on large, flocked bases that enhance the look of the table. I had made four sections two years ago, and always wished I'd bitten the bullet and made more at the time, since in a large ACW game you can never have too many split rail fences. You can see these earlier sections on the left of the photo below.
The fence sections are made of cedar shims bought in packs from Home Depot, split up with an axe (very authentic, I think) then trimmed with a hobby knife and glued together on the base. The bases, as mentioned above, are sections of MDF board, covered with wood putty mixed while wet with different types of model railway ballast for texture, then painted and drybrushed, my standard recipe for bases. Once the fences are painted, I'll flock the bases and add some accent pieces such as rocks, strands of taller grass, etc.
When I get these new sections finished I'll post some shots of them next to some figures. The fence sections are probably too thick and long for real life, but I like the substantial look of them. It's always nice to have these nice big fences between you and that enemy firing line, if only for pyschological benefit!