Host a Spooky Halloween Karaoke Party
Decide where to have the party and create invitations. It is a good idea to co-host the party with other people, which takes some of the stress and expense out of planning the party. If nobody owns a karaoke machine, find a party rental store that carries them and pick out a selection of spooky classics. If all else fails and you can't find a karaoke machine, you can just have music playing and your guests can sing along and perform.
When designing the invitations, specify that all attendees should wear costumes. Decorate the party area the night of the party and prepare some refreshments. Another good idea is to collect a "pizza fund" and order delivery at some point in the night when your guests are hungry.
In addition to a costume contest, also have a karaoke singing contest and award the most entertaining singer with a prize. Don't start the party immediately with karaoke singing, though. Let your guests enjoy some non-karaoke music first. For the adult crowd, music by Rob Zombie, Marilyn Manson, Alice Cooper, My Chemical Romance, and Megadeth are good for getting the party cranked up. Don't waste your money on the "scary sounds" CDs. Most adults find them to be annoying after five minutes and would rather hear music.
Be mindful of your neighbors as your party goes late into the night. It is a good idea to invite them to the party so there will be nobody nearby to disturb!