How to stop IPhone from saying Storage Almost Full?

It does it every 10 mins and it's getting really annoying

You'll have to delete stuff you don't use anymore. Or you could move pictures from your device to your computer to free up some space.

Clear up storage

Delete unused apps. Go through every single app that you have downloaded…
Delete unwanted photos and videos. Boo!
Clear Safari cache…
Delete and re-install Facebook app…
Reset all settings…
Backup and restore…
Backup without iTunes or iCloud…
Turn off iCloud drive

Get rid of files. Then it'll stop.

Check your storage & try to regain some space.