1- Have a theme and a reason for having your social event.
2- Set up a date. Pay attention to other things that may be happening on the day that you will have your event. You do not want to compete with any big event.
3- Set up a place
4- Know how long the event is going to last. Have a set start time and end time.
5- For a dance event - figure out the sound system and the songs.
6- Advertise. Make posters, make it public, and invite people.
7- Have everything ready before the day of the event,
8- On the day of the event, get to the place in advance to have time to set everything up.
9- Enjoy the event, but have a open eye for anything that might go wrong or need to be fix. Unfortunately, many times the people that plan the event enjoy it the least because there are too many other things to focus on. Try to have everything done so that you may enjoy the occasion.
10- Clean up.