1. Apple Wallet
You should keep your phone locked at all times to avoid anyone being able to access your Apple Wallet. This is because there could be a ton of sensitive information stored in your Apple Wallet, including credit cards, ATM cards, and other cards that contain things of monetary value (such as train passes and boarding passes). Make sure you configure your settings in iOS to require authentication like Face ID, Touch ID, or a passcode for Apple Wallet, even when the phone is locked.
2. Airplane Mode
Airplane Mode can be an effective setting when it comes to helping you remain more secure and private. By enabling this setting at times when you can afford to do less on your device than usual, you disable Wi-Fi, Bluetooth, and cellular networks, as well as GPS and location services, all of which keep others from connecting to your device and prevent apps from accessing your location.
3. Lock Screen Access
Limiting Lock Screen Access keeps unauthorized users from accessing sensitive information on your device. These features can include Siri, Notification Center, and Apple Wallet. To do this go to Settings > Face ID & Passcode (or Touch ID & Passcode). Disable Allow Access When Locked for features like Siri, Control Center, Notification Center, and Wallet. You may also want to turn off Reply With Message and Show Previews to keep others from seeing notifications you receive on your Lock Screen.