My local field is covered in bits of wood and jute from sand bags than have rotted. One time my mates use a huge bit of wood (about 4 foot by 4 foot to cover a fox hole i was in and drapped the rotting burlap over a small hole in front that was my observation window. The enemy never did discover my OP, add to that I was carrying two radios (on was on the enemies freq) I was able to provide overwatch and recon.