If you don't want to buy ringtones or the one that came with your iPhone, you can create your ... or a premade ringtone that you grabbed from a free ringtone website. You can also use EzMP3 ...
Connect your iPhone to your computer and launch iTunes or Finder. Choose "Tones" from the sidebar and simply drag and drop your M4R file here. Now, sync tones with your iPhone. Post syncing, navigate ...