Rule #3
Don't run out of alcohol! I know that seems like a given, but if you are serving wine, have enough - assume that you'll serve 1 drink per hour, per guest. That means if you are hosting a party for 30 people, and you get 5 glasses of wine out of bottle, you'll need 7 bottles of wine.... (4 bottles of white and 3 bottles of red, or vise versa)
That is even if not everyone is drinking.. plan ahead!
Plus have bottled water and some soda or punch...
And have fun! Enjoy your party! Have the wine open and ready to go, self serve so you aren't playing bartender all night long.