1: Alphanumeric passcodes
You probably already use a 4-digit passcode, but you can improve that with a 6-digit or alphanumeric code. You change this in Settings>Touch ID & Passcode, select Change Passcode and then tap the small Passcode Options dialog you’ll encounter. Alphanumeric codes are the toughest to decipher, so use one. You should also do yourself a favor and set up Touch ID.
2: Erase data
At the bottom of the Settings>Touch ID & Passcode screen you’ll find the Erase Data toggle. Set this to green and all data on your iPhone will be erased after 10 failed passcode attempts.
3: Two-factor authentication
One of your most powerful protections, two-factor authentication means that when you enter your Apple ID and password for the first time on a new device, Apple will ask you to verify your identity with a six-digit verification code using one of your other devices. Manage this on your Apple ID account page.
4: Find My iPhone
Don’t be a loser – enable Apple’s Find My iPhone (Settings>iCloud>Find My iPhone) on all your devices. You should also enable Send Last Location in order that your iOS device will share the last place it was before battery life expires.
5: Location protection
Your iPhone automatically gather your favorite locations. This can be useful, but you can turn this feature off in Settings>Privacy>Location Services>System Services and then Frequent Locations, which you must turn off. You can erase data that may already have been gathered by tapping the Clear History button. You can also control which of Apple’s system services are tracking your location by taking a look at Settings>Privacy>Location Services>System Services. Here you can review those Apple apps that use your data and disable the ones you don’t use, but don’t disable Find My iPhone.
6: More location
Many apps request access to that data even when you’re not using them. You can review what permissions you’ve given to which apps in Settings>Privacy>Location Services, where you can assign location permission access to each app. Limiting access to this data may limit what some apps can do, but the trade-off is privacy – you can always change the setting when you want to use an app, and are you sure you wanted to share location data with an app you used just once?
7: Who gets your data?
Many apps seem to demand access to personal data such as email, contacts of calendar information. Do you know why? Apps will ask for permission to use this information, but you can change and review how much access you provide to third party apps in Settings>Privacy and select which apps you trust enough to use this data.
8: Hard payments
Is it really too time-consuming to manually approve every purchase you might make on your iPhone? Protect yourself by choosing Always Require when a payment dialog appears.
9: Delete iMessages
Do you want your iMessages to be read by anyone who might break into your iPhone? No? Open Settings>Messages and in the Keep Messages section set 30-days, the shortest period Apple allows.
10: Lock screen
Previews of messages, notifications and emails can appear on your lock screen, meaning anyone in possession of your device can monitor these communications, even if they can’t get into your phone. Change this in Settings>Notifications>Messages and Mail. Maximize privacy by disabling Show Previews so your communications won’t appear on the lock screen.
11: Passcode free?
You can leave Today, Notifications View, Siri, Reply with Message, Wallet visible and (to a point) accessible on your lockscreen, but you can disable this for each of these in Settings>Touch ID & Passcode.
12: Safari privacy
Ads networks want your data. Not only do they want this to sell you stuff, but they also try to make dollars selling demographic information about you to advertisers. Control what you share in Settings>Privacy>Advertising and enable the Limit Ad Tracking toggle. You should then tap the Reset Advertising Identifier tool to anonymize yourself. And avoid using Google services.
13: Use DuckDuckGo
Change your search engine to DuckDuckGo in Settings>Safari>Search Engine, because the search engine doesn’t collect information about you.
Lower the auto-lock time to 30-seconds in Settings>General>Auto-Lock.