Apps that do not work in the phone also become slow. So, review the apps on your phone and remove all apps except useful apps and system apps.
make sure to clear the app cache
If you don’t want to uninstall the app, you can clear its app cache. You will find this option in the storage option in the Mobiles settings.
install system update
If you see system updates in your notifications, you need to install them. With these updates, your smartphone will work better than before.
use the lite version
There are many apps like Facebook, Twitter which take more storage. You can also get the lite version of these apps on the Play Store. You can use them to increase the speed of the Mobile.
SD card format
Using an SD card to increase the Mobile storage can slow down the Mobiles speed. So formatting the SD card is also a great option.