Your iPhone can be customized so it deletes text messages automatically after some time has passed
No. 2- Clear Browser Cache
Whenever you use the Safari browser, it saves some of your browsing data as 'cache' clearing it frees up the memory on your iPhone.
No. 3- Selectively Delete things like apps, media, etc
Did you know apps like Facebook and Pinterest are deceptively large in size and use a lot of space on your iPhone. To find out how your iPhone's storage space is being used follow the instructions below and start deleting