Here are a few tips to help lock down your Facebook account for maximum privacy and security:

Log in securely and log out of unused apps.

When you log in to your Facebook account from a shared or public PC, don’t check “Keep me logged in”. You may also consider logging out of all the browsers and apps that you haven’t used recently. These forgotten accounts are more prone to be hacked.

Reset Facebook Privacy settings.

Go to Settings > Privacy on the desktop version of Facebook or choose “Privacy Shortcuts” from your mobile Facebook app.
Under “Who can see my stuff” you can change the audience for future posts e.g Friends Only.
Under “Who can look me up?” change the settings for your e-mail and address and phone number to “Friends” to make sure only people you know can find your Facebook account by searching your e-mail address or phone number.
Finally choose “No” for the search engines option.
You can also click “See more Settings” for more privacy tools.

Check how much information you share and with whom.

Click the down arrow next to ‘Who can see my stuff ?’ and where it says ‘What do other people see on my Timeline?’ click ‘View As’.
Initially you’ll see what your profile looks like to people you don’t know. Scroll through your timeline and hide life events/photos if necessary by clicking on the edit tab at the top right.

Limit your profile visibility and tame your timeline and tags.

On the desktop version of your website, go to your profile and click the edit tab at the top right to change privacy settings. Change your Friends’ list visibility to “Only Me” or “Friends only”.
Click “Edit” next to the
“Who can add things to my Timeline?” to review what friends post on your timeline before it appears. Under the “Who can see things on my Timeline?” section, you can control who sees posts you’ve been tagged in on your timeline. By default this is “Friends of Friends” but you can change this to “Friends Only”. Finally in “How can I manage tags people add and tagging suggestions?” change the first setting to “On” to approve tags made by others to posts on your own timeline.

Limit access to you and your posts.

To restrict access to your Facebook stuff, click Privacy in the left pane of the Account Settings. Then choose Limit Past Posts under “Who can see my posts?” and Edit to the right of “Who can see your future posts?” in the same section.
Restrict who can befriend you by choosing only “ Friends of Friends” to be able to send you a friend request.
From the privacy menu click ‘More Settings’, and next to where it says ‘Who can look you up using the email address you provided’ and ‘Who can look you up using the phone number you provided’ click ‘Edit’ and select ‘Friends’ or ‘Friends of Friends’ for both.

Protect your browsing.

To make sure you’re using a secure connection, click Security in the left pane of Facebook’s Account Settings and make sure Secure Browsing is enabled.

Prevent people from using your Facebook account.

You can get Facebook to send a login approval to your phone. When you approve it, you can use Facebook. Enable this by clicking ‘Edit’ next to ‘Use your phone as an extra layer of security’ in the Settings page.

Don’t let your apps go berserk.

Many websites and apps allow you to sign up using your Facebook account and in turn, grab access to most of your (if not all) information and your friends’ details. The makers of these apps can also post photos and status updates on Facebook on your behalf, unless you don’t let them.
Always review the app settings and check what access they want.

Beware of scams.

Be careful what you click on Facebook, for chances are it is a scam. For instance, it could be a video posted by one of your friends. And clicking on it allows the makers to post the “video” on your behalf without seeking a prior permission from you, thereby compromising your account’s privacy.