With Freshtunes you can create ringtones directly in your dashboard.
First, log in to your dashboard and go to the Ringtones menu.
Click New Ringtone.
Pick a song from the list and click Create Ringtone.
Here you can set the time frames for your ringtone and listen to the selected fragment before uploading. Duration of the ringtone must not be less than 5 secs and must not exceed 29.8 secs.
When you finish editing and will ready to upload it to the iTunes Store, click Done. If you want to save your progress and come back to editing later, click Save.