1) Reduce screen brightness
2) Don’t use Live Wallpapers
3) Use black wallpaper or black theme
4) Remove home screen widgets that you don’t need
5) Keep your battery away from extreme heat
6) Disable Auto Sync
To turn of auto sync, go to Settings -> Accounts and Sync -> uncheck the ‘Auto-sync’.
7) Turn off WIFI when not in use
8) Disable haptic feedback
To disable haptic feedback, go to Settings -> Sound. Scroll down to system and uncheck Haptic feedback.
9) Turn off location services
To turn off location services:
Tap Settings -> Location services.
Uncheck all the the boxes available.
10) Disable auto updates for widgets
To disable a widget’s automatic updates:
Open the widget and press Menu -> Settings.
Tap on auto refresh and choose None
If you can’t customize the widget and it’s something you can live without, we suggest you to remove it from the home screen. To do that:
Press and hold down the widget until it is highlighted.
Drag the widget to the trash icon to remove it from the home screen.