To make the streams I used a nail to scrape away the grass, painted the cleared area with a brownish-blue acrylic mix, and finally dabbed the painted area with a glossy varnish.
For the road, I used a nail to mark the edges of the road, then dabbed the path with a wet cotton swab, then scrapped the grass away with a flathead screwdriver (it came off with remarkable ease), and then painted the cleared area with a brown acrylic.
Finally, for the fields I've begun cutting out pieces of corduroy and placing them on the American first line. At this point, I placed some minis on the model battlefield. Below part of the North Carolina militia and an American 6-pounder square off against the 71st Regiment of Foot. They won't stay there very long. The fields need yet to be glued down, ringed by fences, and surrounded by model woodland.