If you get an invitation to costume party then you are going to want to sit down and think of what type of costume you want and what you want that costume to do. If you want to be someone, or something, you are normally not then this will get a huge response from everyone that knows you and help you be the life of the party. For example, if everyone that knows you thinks of you as a very proper and well dressed person who seems very educated and always insists that things run smoothly then a great costume for you to wear to a costume party would be to dress as a 1960’s hippie. Make sure you go all out with a wig for crazy hair and some dirt on your face and clothes. You could also go as a biker which would probably shock people even more. Filthy blue jeans, a ripped black t-shirt, and a leather biker vest along with the huge bike boots would probably be the last thing people would expect. You may not even get recognized right away. It should be a fun way to spend your time at a costume party.
If you would rather just simply make people laugh then you can wear a costume designed to be something different that people would find very funny. I am reminded of one costume party I went to years ago where two very attractive ladies dressed as car mats like the kind that would be under you foot when you are driving your car. They had huge foam costumes in the shape of opposing car floor mats and they had things like soda cans and cigarette packs glued to them to look like the things we throw on the floor of our cars. It was a great idea and they won all kinds of prizes that night. You can also do something creative like that. I once remember someone coming to a costume party wearing a long yellow box that just said “cigarettes” on it in huge black letters. He was dressed as a generic pack of cigarettes. Let your imagination go and have some fun with it. After all, it is a party.