Mute unnecessary sounds, such as touch sounds. Tap Settings > Sound and vibration, and select which sounds to keep.
Use wired headphones, rather than the loudspeaker.
Set the device screen to switch off after a short time. Tap Settings > Display & brightness > Sleep and select the time.
Tap Settings > Display & brightness > Brightness. To adjust the brightness, drag the brightness level slider. Make sure that Automatic is switched off.
Stop apps from running in the background.
Use location services selectively: switch location services off when you don’t need them. Tap Settings > Location, and switch off Use location.
Switch on the battery saver: tap Settings > Battery > Battery Saver, and switch on Use Battery Saver.
Switch Bluetooth on only when needed.
Use network connections selectively: Use a Wi-Fi connection to connect to the internet, rather than a mobile data connection. Stop your device scanning for available wireless networks. Tap Settings > Wi-Fi, and switch off Wi-Fi.
If you're listening to music or otherwise using your device, but don't want to make or receive calls, switch the airplane mode on. Tap Settings > Connection & sharing, and switch on Airplane mode. Airplane mode closes connections to the mobile network and switches your device’s wireless features off.