• Clear your history using 'Off-Facebook Activity': This data used to be a well-concealed part of Facebook’s advertising strategy. Not anymore. Adjust and even delete what the company knows through a menu called “Off-Facebook Activity.”   
• The Clear History button disconnects your profile data from your account, which stops Facebook from serving you targeted ads. To completely stop Facebook from gathering analytics reports from other websites, you'll have to log out first.
• The Manage Future Activity tool acts as a more permanent version of Clear History. When you turn it off, it stops companies from sending Facebook ad-targeting data about you.  (Keep in mind that disabling Future Activity prevents you from signing into other apps and websites with Facebook.)

• Tap the three-line menu in the bottom right of the Facebook app.
• Select Settings.
• Scroll down and select Off-Facebook Activity.
• Examine the apps that use your activity and make sure you want to remove the information.
• Tap Clear History.

• Click on the dropdown menu arrow at the top right of Facebook and click Settings & Privacy.
• Select Settings.
• Tap Your Facebook Information in the left column.
• Click Off-Facebook Activity to review. From here, click Manage Your Off-Facebook Activity.
• You’ll be asked to re-enter your password. Once you’re verified, it will show you the apps and sites that have shared ads with your Facebook account.
• When you’re ready to clear this information, click Clear History.

Who Can Contact You

• Click on the padlock icon on the top toolbar (on the right hand side), then click 'Who can contact me'.

• By default this is set up as ‘Basic Filtering’ to allow friends and people you may know the opportunity to send you a message. If you want only friends to be able to contact you, you can increase the filtering on your inbox. Other messages will then be diverted to your ‘other’ folder which you can access from the Messages screen.

Strict Filtering

• To do this, click ‘Strict Filtering’ under ‘Whose messages do I want filtered into my Inbox?’  From this area of the screen you can also limit who is able to send you a friend request, choosing between everyone or just friends of your friends.

Friend Requests

• Never accept Facebook friend requests from unknown people. Scammers find your information through Facebook or other social media accounts. Some set up fake accounts and send out friend requests. When you accept the request, they can view your friends' and personal contact information. Other scammers rely on social media users not locking down their privacy settings, so basic information, such as your name, email address, and friends' names, is publicly available.

Notifications

• Consider enabling login notifications, so you will know when someone uses a new device to access your account.

• When accessing Facebook from public wi-fi in places like hotels and airports, text "otp" to 32665 to receive a one-time password to your account.

Timeline Posts

• Make sure only your friends can see your timeline posts.   While certain elements of your profile are viewed by everyone, many other aspects of your timeline can be blocked.

Future Posts 

• Make sure all your future posts are locked down. Click on the padlock icon on the top toolbar (on the right-hand side), then click ‘Who can see my stuff?’
• Under 'Who can see my future posts', choose from:  Public, Friends, Only me, Custom (which allows you to limit some of your friends from seeing your posts).  Pick what’s best for you, but make sure ‘Public’ isn’t selected. Whatever you choose will then become the default every time you post an update (though you still have the option of selectively changing this for each individual update you post in the future).

Previous Posts

• Click the arrowhead on the top toolbar (on the right-hand side). Choose  'Settings' > 'Privacy Settings'

Login Approvals

• You can choose to have an extra layer of security when accessing your account from an unknown browser. Facebook will send a code to your phone which you will then need to use to login.
• Click the arrowhead at the top right of any page and choose ‘Settings’, then ‘Security’ from the left-hand menu, then 'Login' approvals. Check the box that says ‘Require a security code to access my account from unknown browsers’. Facebook will then take you through the process of setting up login approvals so click on ‘Get Started’ to begin,
  Once you have set up login approvals you will only need to enter a code when you try to log in from a new device. It is a feature that makes it that much harder for a hacker to gain access to your account and as such is well worth enabling.  Note: if your browser clears your history on exit, or has private browsing switched on, you may need to enter a code every time you log in.

Privacy Settings

• Click Privacy on the left-hand menu, and under ‘Who can see my stuff’, click ‘Limit past posts’. From here you can change all your past post visibility to ‘Friends’.

About Us Section

• On your timeline, click ‘Update info’ and then click ‘Edit’ next to the area you wish to change the visibility for. Choose from the options of ‘Public’, ‘Friends’, ‘Only me’ or a 'Custom' list of people.

Links

• Don't click on strange links, even if they're from friends. Notify the person who sent you the email if you see something suspicious.  For example, you receive an email that appears to be sent by a friend or family member. The message addresses you by name, but the content is strange. Usually, it's just a link to a website. If you click on it, you could end up downloading malware to your computer. 

Hide your location

• Go to the phone’s Settings and tap Privacy.
• Tap Location Services, followed by Facebook.
• Tap Never to disable location services.

• Go to the phone’s Settings and tap Privacy.
• Tap Permissions Manager, followed by Location. Choose Facebook.
• Tap Deny to disable location services.
• Once you’re finished with adjusting your phone’s permissions, follow these steps to disable location tracking in the app:
  
  
• Tap the icon with the three lines in the bottom right.
• Tap Settings & Privacy, followed by Privacy Shortcuts.
• Tap Manage Your Location Settings, followed by Location Services.
• Tap Location and select Never.
  

Disable Facial Recognition

• Click the downward-pointing arrow in the top right of the screen.
• Select Settings & Privacy, followed by Settings.
• In the left column, click Face Recognition.
• Tap “Do you want Facebook to be able to recognize you in photos and videos?” Select No in the drop-down menu to disable the setting.
  

Get rid of apps that track you off Facebook

• Logging into other platforms or websites with your Facebook username gives those companies access to your personal data and may permit them to share your activity with Facebook.

• Click the downward-pointing arrow in the top right of the screen.
• Select Settings & Privacy, followed by Settings.
• Tap Apps and Websites on the left menu.
• Select Active.
• Click on the box next to the app’s name to stop tracking you and click Remove. This will disable it from tracking you.

Enable two-factor authentication to lock out hackers

• Click the downward-pointing arrow in the top right of the screen.
• Tap Settings & Privacy, followed by Settings.
• Select Security and Login. 
• Scroll down to Two-Factor Authentication and tap Use two-factor authentication.
• Enter your phone number and confirm the code in the text to complete the setup.

Stop Google from showing your Facebook account

• On your computer, open Facebook and click the downward-pointing arrow in the top right of the screen.
• Tap Settings & Privacy, then Settings followed by Privacy.
• Under “Do You Want Search Engines Outside of Facebook to Link to Your Profile?” click Edit.
• Click the checkbox on the bottom to turn off the setting.

Limit the audience for your personal posts

• Open Settings & Privacy again, then Settings and click on Privacy.
• Scroll down to Who can see your future posts? and click Edit. You can adjust the settings for specific audiences here.
• Scroll down to Limit Past Posts to change who can access your previous content.
• People accidentally share all kinds of personal facts and information without realizing it. Changing this setting can protect you from getting phished or stop a hacker from correctly guessing one of your security questions.

Stop your activity from being advertised.

• Under Settings & Privacy, select Settings, then click Ads, followed by Ad Settings.
  Click Social Interactions and select Only Me.
  

Avoid those Like and Share buttons on other parts of the web

• Whenever you use a Facebook button on another website, you're feeding Facebook's ad machine. Every Share, Like and recommendation, becomes part of the data feed that Facebook uses to tailor its algorithm.  If you must share something, do it the old fashioned way by copying and pasting it into a post.

Clean up your Friends List

• On the dropdown that appears, you’ll be able to select Unfriend. Do this for anyone you’re not 100% sure about or don’t know closely.