Yes, one of the gripes about iPhone is the difficulties of making custom ringtone(s) where other smartphones can easily use mp3 files directly as ringtone.

The video shows how simple it is to create a ringtone from your mp3 music audio files using iTunes which you should already had installed.

1. Open iTunes and select your favourite MP3 audio file.
2. Listen to the song and find the part of it you want to use. The chorus may be a good place to start.
3. Write down the start and stop times of the clip.
4. Select the Pull down menu of the iTunes & select preference
5. Select the “Import Settings”
6. Change the Import Using to “AAC Encoder” with high quality 128kbps
7. Right-click (Cmd-click for Macs) on this file in your library to bring up the context menu.
8. Select Get Info
9. This will open a new dialogue box showing various details about the audio file. Select the Options tab.
10. Check the boxes next to both Start Time and Stop Time and enter the times you want your new ringtone to start and stop (the maximum length is 40 seconds) then click OK.
    This will return you to your music library.
11. Right-click (Cmd-click) on the same music file again and this time select Convert Selection to AAC.
    iTunes will process this briefly and insert the new ringtone-sized file under the original file in your library.

12. Right-click (Cmd-click) on the newly created file and select: “Show in Windows Explorer (or Finder on a Mac)”
    A new dialogue box will open showing you the location of this file. Select the file and rename it, changing the file extension from “.m4a” to “.m4r”. Windows will warn you that this change may make the file unstable, but continue anyway.

13. Back in iTunes, delete the ringtone file you’ve created from your library
14. import the renamed “.m4r” file into your library.
15. Connect your iPhone and sync your playlist.
16. You may have to manually drag the .m4r file into the “Tones” section on your iPhone. With your iPhone synced this file is now ready to be used as a ringtone.