Faux spiderweb are the best bang for your Halloween decorating buck. You can pick up bags of them at almost any discount store for anywhere from 1 to 3 dollars each. We buy as many as we can at 50% off the day after Halloween.
One of my goals every year is to immerse everyone in spookiness. I have found that if you decorate literally from floor to ceiling, it’s easy to pull off. You can create a “false ceiling” using spider webs that will have your guests feeling like they just walked into a haunted house.
Grab a hammer, some small nails, a ladder, and a friend to help you stretch the webs across the room. Going diagonally, crossing over other webs helps add to the illusion. Make sure to go the full length of your room for the full effect. Cover mirrors, and picture frames for that haunted house effect.
You can partner the spider ceiling with “scene setters” which have become very popular the past few years. These rolls of vinyl wall paper like material can transform your room into a multitude of things from woods and a cemetery to a castle or morgue. We used these for several years to give the illusion of eating in a cemetery using rolls of trees and stone walls.