There are a few tips that you can follow to improve battery life of your smartphone
1. Turn OFF radio services i.e. WiFi, Bluetooth and GPS, when not needed.
2. Keep screen brightness on Auto Mode.
3. Use Bluetooth tethering or USB tethering (when you have a cable) instead of portable WiFi hotspot to share your phone’s data service.
4. From the home screen, hold the home key to close the recent apps running in background.