Matt Elliott, writing for CNET, lays out some solid tips here. My favorite:

Another way hackers can get into your iPhone or at least buy some time to find a way to circumvent your passcode is to enable Airplane mode via Control Center from the lock screen. Once it’s in Airplane mode, you won’t be able to track it via Find my iPhone.

To prevent Control Center from being accessible from the lock screen, head to Settings > Control Center and toggle the [switch] off for Access on Lock Screen.

This is a solid tip. Remember, all you are doing is removing Control Center from the lock screen. If you unlock your phone first, Control Center and the easy access to Airplane Mode, is still just a simple swipe-up away. And given how quickly Touch ID unlocks your phone, I don’t see any down side to making this change.