Turn off any services that aren't currently in use, such as Bluetooth or Wi-Fi.
Avoid using Live wallpapers.
Turn off Location Services when not in use.
Disable auto-update apps.
Disable auto-sync to prevent automatic collection of data. Remember to turn back on to allow apps to download new data like email and social media posts.
Disable Mobile Data to prevent all web-based background processes from occurring. Remember to turn back on to use 4g service.