So I just tried creating some of my own ringtones by trimming songs down to be less than 30 seconds. Next, I exported them as MP3 files and then followed that up by importing them into my iTunes library.
iTunes then gives you the option to create AAC files – do this by right click on the file from the iTunes library and select “Convert Selection to AAC”. Once you have an AAC file, the tricky part is trying to figure out how to get it into the Ringtones folder. I’ve tried copying the files into /iTunes/iTunes Music/Ringtones/ with no luck so far.
If you have any suggestions, please let us know.