How do I add ringtones to the latest iTunes?

How do I make custom ringtones for my iPhone?

So to set your custom ringtone as your ringtone or text tone:
  1. Go to Settings on your iPhone, then tap Sounds.
  2. Tap Ringtone or Text Tone, whichever one you want your custom sound to be for.
  3. Select your custom ringtone from the Ringtones listed.