Have a set ending time. Stop serving alcohol an hour before the party ends. Have a plan for guests who drink too much. As host, you bear some responsibility for their actions after they leave the party. Dilute drinks with non-carbonated beverages.
Carbonation quickens the effect of alcohol.
Have some friends commit to being designated drivers. Just because people say they are OK, doesn't mean they are. If an individual is drunk and abusive call the police and let them handle it. Be aware of your own drinking. Being in control of the party means first being control of yourself.