Lean a branch against the wall underneath your paper bats. Use some cotton wool to imitate spiderwebs on the branch. Put an old wooden crate in front of the branch. Put one or two larger pumpkins in front of the crate. On top of the crate put one large pumpkin and a few smaller ones. Position your paper crow on the wall to make it look like it is sitting on the branch. For some spooky atmosphere you could also hide a small tablelamp behind the crate.