Scuse me for bellowing out loud with laughter at the maggot story.
As far as backgrounds go, a nature photographer I know has an interesting technique. For example, he might want to photograph poppies in a field of corn, but knows that the various out-of-focus poppies in the background will be a distraction. He finds a section of the field without any poppies, throws it completely out of focus, photographs it, then prints it up quite big, mounts the image on card and uses it as a portable background in the field. He has dozens of these things and has worked out how to use them extremely convincingly - you would never, ever know they weren't the real thing. Sounds naff, but it really works! (Of course, he's probably shooting digital now, in which case I doubt he needs to worry about it any more!)