1. Turn the phone off when going to sleep or charging it.
2. Stop searching for a signal.
3. Follow the method of full charge and full discharge.
4. Switch the vibrate function off on your phone, using just the ring tone
5. Turn off your phone's keypad light during day time.
6. Avoid using unnecessary features.
7.Keep calls short.
8. Turn off Bluetooth, when ever is not in use.
9. Same goes for WIFI, GPS, and infrared capabilities, if your phone has these features built in.
10. Turn the brightness of the display to the lowest setting possible.
11. With a smartphone, avoid using moving or animated pictures or videos for your background or ringing tone.
12. Use a black background whenever possible.