I took a 24" x 36" painting canvas (I think that's the size) and took the canvas off and mounted it to a couple of pieces of 3/4"x5"x3' planks of plywood that I joined together for the overall width.
I then painted the canvas white, and while it was still wet I applied a thick layer of dry-wall paste on top of it and used a paint scraper to give it texture.
While that was drying I hot-glued scrap wood together to make the barn and stained and painted it. Once the canvas was dry I stained the sky and painted the fields. I then attached the barn and other items using nails and hot-glue.
There are a couple of little pieces here and there that I used to get the overall look.
Hope you like it. Give it a shot. See what you having laying around and think of something you can recycle it into.
Oh, and of course - the inspiration: