The NSA releases a Best Practices Guide for Mobile Devices
Whenever you receive a software update for your device or your apps, install it as soon as possible. Do not use your device to text sensitive information and never open unknown email attachments and links. You should only use original charging cables and accessories from a trusted manufacturer and stay away from using public charging stations. Unexpected Pop-Ups can be malicious. If you get one, force close all open apps by swiping them away. The NSA also suggests that you do not jailbreak your iPhone or root your Android phone.
The second page of the NSA’s Best Practices Guide for Mobile Devices
You should disable Location Services when not needed and turn your phone off and back on once every week. The latter will help protect you from zero-click exploits that can attack your phone even if you don’t do anything to unleash the malware such as tapping on a link or downloading a file.
If you want to reduce the odds of having your mobile device hacked, you should consider the suggestions made by the NSA. After all, when it comes to security, it’s part of the NSA’s name.