No good Halloween party could be void of spooky, creepy, candlelit, carved Jack-O-Lanterns spreading eerily dim lighting throughout the room. You can also buy ghostly glowing images to hang up in strategic locations and add imitation spider web or goassmer cloth to walls. Either one will create a scary haunted house feel to your party.
Suspending decoration items like bats, flying witches on broom sticks, large hairy spiders, balloons with ghostly faces, skeletons and the like from the ceiling, down to to face level, will have your guests dodging around among these horrors in the flickering candle light, and always on the lookout for their next fright. Distributing plastic spiders and other shocking surprises around where people sit, or on tables among the drinks and plates, will help to keep your guests on edge.
If you hang a number of thin threads from the ceiling in different parts of the room they will not be noticed in the subdued lighting, but will be felt unexpectedly as your guests move around. This can be a surprising sensation, and suggests a ghostly presence that will often get a shrieking reaction from your guests.
The unexpected is often quite scary. Set up some frightening pictures and other decorations that are placed in front of timed lights. When these scary scenes are suddenly illuminated, or better yet, combined with loud, frightening sound effects, everybody will be surprised enough to jump out of their seat. If you invite a more adult crowd, your lights could reveal a headless corpse hanging in the darkness.
Combining good lighting effects with a fog machine can really make things creepy. To make the effect authentic, hide the fog machine behind some cleverly placed tombstones or other decorations.
Another great touch can be a horror movie. Just put on an especially scary film on a big screen TV and let it play quietly in the background. It will add a chilling touch to your party.
Before the party really gets going, you can use frightening music and sound effects with some classic Halloween tracks like the Monster Mash to set the mood. When things pick up and dancing starts, you can still throw in some scary sounds here and there to maintain your spooky atmosphere throughout the evening.