Select only the sounds that you need: Mute unnecessary sounds, such as key press sounds. Tap Settings > Sounds and under Other sounds, select which sounds to keep.
Use wired headphones, rather than the loudspeaker.
Change the phone screen settings: Set the phone screen to switch off after a short time. Tap Settings > Display > Sleep and select the time.
Lower the screen brightness: Tap Settings > Display > Brightness level. Make sure that Adaptive brightness is enabled. To adjust the brightness, drag the Brightness level slider.
Stop apps from running in the background: Press check_box_outline_blank and close the apps you don’t need.
Enable the Background activity manager. The notifications of some apps or emails may not be able to be retrieved instantly. You can manage the battery life by adding apps to or removing them from the whitelist. Tap Settings > Battery > Background activity manager.
Enable Battery saver. Tap Settings > Battery > Battery saver, and switch to On.
Use location services selectively: Switch location services off when you don’t need them. Tap Settings > Location and switch to Off.
Use network connections selectively:
Switch Bluetooth on only when needed.
Use a Wi-Fi connection to connect to the internet, rather than a mobile data connection.
Stop your phone scanning for available wireless networks. Tap Settings > Wi-Fi and switch to Off.
If you‘re listening to music or otherwise using your phone, but don‘t want to make or receive calls, switch Airplane mode on. Tap Settings > More > Airplane mode.
Aeroplane mode closes connections to the mobile connection and switches your device’s wireless features off.