1. Keep everyone in either the backyard or house. This is so that a random patrol car just driving by doesn't know your having a party.
2. If you know your neighbors and they're not total assholes, mention to them that your having a party and if the noise gets out of hand, to please call your cell instead of the police.

Agreed on the smoking point. If you can't have smoking indoors, keep a really close eye on whoever's smoking outside-- 90% of the time they're the reason I get noise complaints at parties I'm at.

Also be careful with the volume of the music-- if it's loud, people will talk over it, and then people who want to hear it will turn it up again. If you want to bring down the volume of the party, bring down the volume of the music and often people will follow.

It also can't hurt to get a couple of people to be your "helpers" with controlling the noise-- brave people who aren't too worried about being rude who will shush loud guests for you.

Also consider making up something about noise complaints with previous parties (if that's believable).

http://www.wikihow.com/Deal-With-the-Police-when-They-Come-to-Your-Door-at-a-Party

Some good points there, but you do not have to answer the door when the police show up. Keep the doors locked and closed so they can't just walk in. Also, other than verifying who you are, don't talk the police without a lawyer there. All they're going to do is use what you say against you.

Keep it inside and under wraps. You just need to make sure doors/windows are closed so sound doesnt get out. As soon as people start opening doors and going out to smoke you have problems with large groups outside, have a smoking room indoors!!! If the cops DO show up throw the women at them and hope that they flirt well.

Keep the windows and blinds closed because if the police look in and suspect someone is underage they can come in without a warrant.