Facebook wants you to share as much information about yourself as possible. It wants your friends to do the same. After all, the more personal details you feed into the network, the less likely you are to pack your data suitcase and leave. Advertisers tend to like all that data too. All this means your default privacy settings probably don't jibe with how you want to actually share your information.
Luckily, you're not defenseless. With a few small setting adjustments, you can take back control and make sure you share only what you want with the world.
One key thing to remember before we proceed though: The Internet is forever. Once you have posted something online, it does not belong to you anymore. If you've shared a photo or status update with anyone, it's possible that they could screenshot it and share it with the world. So when in doubt, don't post it.
Lists
One of the most useful ways you can optimize your Facebook sharing is to share updates with a select group of people (close friends, family, coworkers) through the creation of lists. Even more than privacy, lists are useful for only sharing information with those who are likely to be most interested.
To create a list or manage ones you've already got, go to the Friends section in the left-hand navigation panel, then click "More," which is to the right of the Friends header. There, you can see all of the lists you've created and edit their members. You can also create a list by clicking "+ Create List," naming it, and adding the friends you'd like include.
Privacy
Now on to broader control of your privacy settings. Click on the privacy control icon in the upper right of your Facebook home screen, then click "See More Settings." We'll start with the "Who can see my stuff" section. In the drop-down menu, click "Custom." If you want to keep it simple, you can opt to share only with Friends. This allows your posts to be shared with friends of those you tag in your photos. If you want tighter control, uncheck the box for sharing with "Friends of those tagged," and specify who (your mom, your boss, or specific lists) you don't want future posts shared with.
Next, limit the audience for old posts on your Timeline. Do you remember what you posted five years ago? Yes? Well then you probably want to hide it. No? You definitely want to hide it.
To adjust what shows up on your Timeline, the simplest -- albeit still tedious -- way is to go through your Activity Log. There you can see what items you've commented on are public, specific to a group or list, or Friends only. Facebook keeps track of every action you take. If you liked a post that could be deemed unsavory in the future, here you can unlike it so it doesn't show up on your Timeline or through Facebook Graph Search.
In the "Who can contact me" section, if you often meet new people outside your usual social circles, you may want to leave "Who can send you friend requests" open to everyone. Otherwise, you can limit the friend requesting to Friends of Friends. The default of Basic filtering should be fine when it comes to what messages you want filtered to your inbox.
Next, a big one: How searchable do you want to be? That is, who do you want to be able to look you up with your email address and phone number. To stay on the safe side, I recommend Friends only. If you meet someone you definitely want to Facebook friend and they can't find you, simply adjust this setting temporarily (or search for them, if their privacy settings are looser). Keeping this setting locked down reduces the amount of spammy and unwanted friend requests you get.
Similarly, you'll want to limit "Who can look up your timeline by name?" to just your friends (if you've still got this setting, which is being removed this year)1. If a friend of a friend wants to check out what you've been up to all year, you can friend them first. Most of us don't want strangers peering through our Facebook history. So for the next setting, unless you're 100 percent confident your Facebook profile is squeaky clean, switch "Do you want other search engines to link to your timeline?" to Off.
Timeline and Tagging
Keeping control of who can view what on your Timeline, as well as your tagging settings, comes down to personal preference. But if you want to veer towards the secure side of things, the screenshot below shows the settings you should switch to.
It's always a good idea to review the photos you've been tagged in before they get widely broadcast to your friends. Maybe you didn't want to share that you were raging at a kegger till 3 a.m. last night, for example.
For "Who can see posts you've been tagged in on your Timeline," you can set it to Friends only as a default, or (as I've done) Friends, with the exception of some of your lists.
Security
Towards the top of the left-hand navigation panel is a header titled "Security." You'll want to enable both Secure Browsing and Login Notifications (which lets you know if your account gets logged into from a new browser or device) for both email and text/push notifications. As another security precaution, we suggest enabling approvals for logging in from an unknown browser and enabling Code Generator, which adds a layer of security when linking an app to Facebook.
Blocking
Got one person that keeps annoying you with constant event invites? Tired of receiving app invitation requests for the latest Facebook gaming fad? Under the "Blocking" section, you can block specific users, app invites from specific users, event invites from specific users, or invites from specific apps.
Apps
And if you haven't already, here's how to control which apps your friends can see that you use, as well as what information your friends can access about you through their apps.
1 Correction 12:18 EST 08/31/13: Updated to denote Facebook is retiring the “Who can look up my timeline by name?” setting this year
