There are a few tips that you can follow to improve battery life of your smartphone
1. Turn OFF radio services i.e. Wi-Fi, 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 Wi-Fi 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.