Keep things in perspective. (It's not the end of the world).
Allow yourself a quiet weekend to grive alone if need be.
Afterwards make it a point focus on things you probably have been neglecting because the of relationship. (hobbies, going to movies, concerts, and other things with friends and families)
If at all possible cut off all communication with your ex for at least one year. Staying in contact often leads to someone getting their hopes up for getting back together. Instead it becomes a yo-yo relationship or booty call situation.
An ex is usually an ex for (a very good reason).
Remember your future is ahead of you and not behind you!