Loading ringtones onto Iphone without buying from Itunes?

How do I do this? I have a lot of ringtones from old phones. The Iphone 3's were easy to load them but this phone doesn't seem to want to. I don't want to use them as music I want them as ringtones

Well first of all it would be more helpful if you said what Gen your IPhone is. You can download some apps from the app store that gie you free ringtones which is good. But do not know how to put your previous ringtones on there, sorry.