Everyone seems to have their way to make a ringtone. There are aspects of Garage Band which I find cumbersome, but you need Garage Band to create and transfer your ringtone to your iTunes library. Try this.
1. Download and install Audion 3, a free Mac mp3 editor (
http://www.panic.com/Audion/
2. Open Audion 3, then under File go to "open mp3 in editor.
3. Navigate to your song via home/music/itunes/itunes music to the folder and then mp3 you want to make into a ringtone
4. Identify which brief section you want for your ringtone, say from 22 seconds to 52 seconds of the song, drag and highlight that section in the mp3 editor, then under Edit click on Copy.
5. Go back to Audion 3 and under File click on New mp3 editor. Paste your saved file into that space. Under File again click Save As, give it a name and the suffix .mp3, save to your desktop.
6. Open Garage Band, iPhone ringtones, loops, choose
7. Delete anything which Garage put in main space, then drag your mp3 into that space. After it sets up, go to share and send ringtone to iTunes.
8. Sync. Be sure your check Sync all Ringtones, otherwise you have to individually click on your new rintone.
