Small cracks on the surface of a cell phone can cause moisture/steam to seep in, which can gradually erode the circuit board. Avoid using your phone in the rains.
Keep your cell phone away from a magnet. The magnet in your phone speaker will absorb excess iron powder if exposed to a magnetic field.
Give a breather:
Enclosed metal spaces like elevators and cars may require the device to work harder for establishing a connection, thereby draining the battery faster. So avoid using your cell phone is such areas.
Switch off your cell phone before you charge it. Charging a cell phone while it is switched on decreases the battery life drastically. Save from extremes: Never leave your cell phone in direct sunlight or at very cold area. Drastic changes in temperature may hamper the phone’s internal components.