I finished the marsh area in green paint. The edges were done with Durham's Water putty then painter brushed with glue and flocked with a mixture I cooked up. I got the sheen with Future but it can be had many different ways. Easily with Elmers too. The sand is a Renaissance Ink basing mix medium but all you have to do is mix sand and glue to get the same thing.

Buy Citadel's terrain book and you can follow the method a bit more closely.