1.) Apathy. Who cares man. It's a party. Someone pee's in your ancient oak chest that your family got while travelling the Oregon Trail, who cares. You wanted to burn that thing anyway.
2.) Always invite 3 guys to every 5 girls. This prevents sausage fests.
3.) Slip and slides. Every party needs one.
4.) Don't go around desperately inviting more people in the middle of the night. If you build it, they will come.
5.) Invite Terry.