Another decorating idea:
Tombstones!
I made some tombstones for my party this year.
I got a 2mx2m sheet of hard thick styrofoam from the local home improvement center (about $9.) I cut that into 2 tombstone shapes.
I took some thin styrofoam ($3 per sheet) and cut out two designs for the engraving. Some people actually engrave with a wood burner or dremel but that's just too much work for me. I glued the engravings on with regular wood glue.
Then I bought some gray water based house paint and coated the tombstones. While the paint was wet, I took some black paint from a kid's paint set and made some streak marks for an aged effect. DONT USE SPRAY PAINT! The aresol will melt the styrofoam.
I'll add in pictures of them in the graveyard scene after my party.