First of all, list down the people you would like to invite to the party. When you have gone through the entire list, send invitations to all of them some time before the party. There should be considerable time between the invitation sent and the party so that the guests have the time to decide on their availability to you.
A Halloween Party is incomplete without music. Make sure the music is energetic so that the party remains lively throughout. You must hire a nice DJ who can manage the affairs for you.
Games for adults
It should be a fun themed party and you need to make sure that all the guests enjoy to their fullest. There should be a variety of activities so that they enjoy every moment they have spent at your place. The games may include darts, pool or karaoke.
To make it more interesting, you can award prizes to the guests. Make sure you keep a number of prizes in different categories. A list of popular ones include Best Dressed, Worst Dressed, Best Couple, Best Costume etc.
This is probably the most important part of the party. You need to make sure there is abundance of drinks in the party. An unlimited supply of beer or other drinks will set the tempo in your favour.
The party needs to be decorated according to the theme. You should keep the theme colourful so that it matches the occasion.