Next, by clicking on “Applications and Websites” on the privacy settings page, you can edit whether your friends can share your birthday, photos, and other specific information. Remember that applications can access your “publicly available information” no matter what.

The security firm Sophos recommends users set their privacy settings for two of Facebook’s own popular applications, notes and photos, to friends only.

5. Go over your list of friends.

The average Facebook user has 130 friends. But many people interact with a much smaller group when commenting on status updates, photos, and links. So it doesn’t hurt to occasionally review your list of your friends to get an idea of just who can view your status posts, vacation photos, and funny links you’ve shared over the years. Don’t feel obligated to add anyone as a friend, even if that person adds you first. For professional acquaintances you don’t want to snub, send them to a LinkedIn profile you can set up. Some workplaces and schools have rules about Facebook interactions between bosses and employees or students and teachers.

6. Create custom friends groups.

If you have friended a lot of people, sort them. Think of the groups you interact with in real life–co-workers, college buddies, girlfriends, grandma and grandpa–and organize your Facebook friends in these groups, too. Go to “All Friends” under the “Friends” button up top, and click on “Create New List.” Then decide what aspects of your profile, and which status posts and photos, these people will have access to. Or, simply create a “limited” list for acquaintances or distant relatives and limit their access.

7. Customize your status posts.

When you type something into your status update box, click on the little lock icon. You’ll see a range of privacy controls pop up, letting you either allow or limit access to the post. If you want, you can even hide it from everyone by clicking “Only Me” under the custom settings. Click on save setting. Repeat with each post, or create a default setting for most updates and increase or decrease privacy as you see fit.

8. Let your friends know you have boundaries–in person.

Facebook users might have woken up on a Sunday morning to find that an overzealous friend has posted dozens of photos from that wild party the night before–the good, the bad, and the hideous. Chances are, they didn’t do this to embarrass you, though if they did you have bigger problems. Rather, they probably don’t know that you don’t want these photos posted. Go ahead and tweak your photo privacy settings on Facebook, but if someone starts snapping pictures of you at a party, ask them to check with you before posting the photos anywhere.

9. Never assume complete privacy.

Even for the most tech-savvy person, unflattering photos, incriminating text messages, or angry status posts about work have a way of worming their way out in the open. So always be careful what you post.