Verify a current backup
Do not assume that seeing a cloud icon means every important app or file is included.
Know account credentials
Device migration often depends on the Apple or Google account used on the old phone.
Follow the manufacturer's transfer process
Current transfer tools change over time and should be used from official guidance.
Erase only after verification
Do not wipe the old device until the new device or backup has been checked.
General consumer technology information only. Interfaces and menu names change. Before resets, reinstalls, storage changes or other major actions, verify that important data is backed up and use current manufacturer/service-provider instructions.