Purchase inexpensive foamboard and cut into gravestones, using a wooden spoon handle engrave names and dates, wash over with watered down black paint.
Use red and black lightbulbs
Place "cobwebs" in corners and on furniture
Make recordings of haunting sounds
Buy inexpensive styrofoam heads at beauty supply stores and paint them like "zombies" Add fake blood and you are all set for some scary times.
Serve ghoulish punch, mix jello with green punch and let harden just a little. Serve in a platic couldron with a hand. (freeze punch in a latex, unpowdered glove tied tightly at the wrist)
Create a quick, scary snack with microwave popcorn. Place popcorn in a large bowl (or individual bowls) and add gummy worms crawling out the sides.