I haven't done it in like a year or so, but it's fairly easy in Garage Band if you have a mac. I made a couple of my own custom ringtones. When you're done with your project in GB, you just upload it to iTunes and create your ringtone. It's not that hard, just get crackin', you'll figure it out. If you're on a windows machine, I personally don't know of any other software that will help you achieve this. I would think there's gotta be something out there though for that side of the world....