Hi Pal,
Except using Apps, Uninstall the Inbuilt Unwanted Apps & the Useless Games.
Whenever you want that Apps, just download it from Playstore.
Switch off your mobile for 15mins for twice a week & you can extend the mobile’s Lifetime.
Use any Booster contained Launchers, in this my suggestion is “APUS Launcher”.
Cleanup the Junk files, in this my suggestion is “Clean Master”.
Good Luck !!