I have done the mistake of upgrading the firmware without having a copy of stock or factory firmware and I know the pain of bricking the device. This is not only for hobbyist or custom ROM lovers. Many Nexus device were reported to be dead because of firmware error supplied by the OEM and many devices reported lower battery life after upgrading to Lollipop from Kitkat. Now they can’t downgrade because they don’t have the firmware. You should always find a copy of stock and original firmware that matches your device and region before upgrading to another. It saves you from risk and gives chance for rollback and repair
Many people cry over lost contact after reseting the phone to factory default settings. This can sometimes be very serious. So before doing a reset, formatting or upgrading the mobile always make sure you have made a backup file of contacts. This can also be done by syncing the contacts with Google account using Contacts:Files and folders:
This is the basic thing. We all love our music, pictures, videos and documents. I think this is the thing I shouldn’t be telling because they are the most basic things that must be extracted first to safe place. Create multiple copies in multiple location like PC, Laptop. I also suggest to put a copy in Cloud but mmake it sure by using stronger password or using premium version.Apps Data:
Application can be downloaded and installed anytime but the important and valuable data like safe files and settings can’t be restored. There are many applications available like Titanium Backup etc that helps to create backup of both application and its data so that it can be extracted later for future use. Try other apps but make your data secure.
Settings like data connectivity for network operator or carrier is important. Save the settings by writing the configuration in a page or file. Create and keep the settings,calibration, PIN code, PUK Code, Security code and personal settings safe with you in offline or non digital means like copy or paper.
These are the most basic things that should be taken care of before upgrading or formatting your smartphone or tablet. If we have left anything feel free to drop it in the comments section and we will be happy to add it.