Use Blocking and Privacy Settings
A significant percentage of relationships end with bad blood and anger. To avoid drama on Facebook, instead of seeking vengeance, use your excess emotional energy to focus on your steadfast friends. In this regard, Facebook's privacy settings are extremely helpful.
You may want to begin by blocking your ex and some of your mutual friends. When you block another user, it means you'll remove that person from your list of friends and your profile becomes invisible to him or her. In turn, that person's profile will become invisible to you.
The simplest way to block someone is to visit his or her profile and click Report/Block This Person at the bottom of the page. When you're done, you're immune to pokes, messages, and wall posts from the blocked person. There's one exception -- if a mutual friend posts content to Facebook, you'll both be able to see each others' comments. In the event that you're trying to sever all contact with a person, that's a loophole worth remembering.
Facebook's customizable privacy settings also let you control the information you share with others. With just a few seconds of tweaking, you can create custom settings that let only your friends see your status, photos, tagged photos of you and relationship information.