Recent research has revealed that ringtones are slowly becoming a thing of the past. Data shows that downloads have dropped by a quarter in the last few years, more than a decade after the Crazy Frog song earned its Swedish creator £40 million when it was released in 2004. A survey also found that only a small percentage of 16- to 24-year-olds consider phone calls to be important, causing their phones to vibrate instead of ringing. You can still customize your phone's ringtone, however. You can set the default ringtone and assign different tones to certain contacts.
You can also use vibrations and turn off the doorbell. I know many people who personalize ringtones for family members or work (using the pre-installed ringtones on their phones), but that's about it.