There are many things that can be customised on the iPhone including ringtones. A specific ringtone can be set for a specific contact, or one ringtone can be set as the default ringtone. If you'd like to get new ringtones for your iPhone, you'll find that the process is very easy when using the iPhone's built-in iTunes app.
Press the "iTunes" icon on your iPhone to launch the iTunes app.
Press the "More" icon on the bottom of the iTunes app.
Press "Ringtones" button.
Search for ringtones by "Featured," "Top Tens," or "Genre" categories by pressing any of these three buttons.
Select a ringtone to download to your iPhone by pressing the ringtone name and then by pressing the "Purchase" icon. Type in your Apple ID user name and password and press "OK" to begin downloading the ringtone. You can listen to the ringtone before buying it by pressing the name of the ringtone.
Press the "Settings" icon and press "Sounds" then "Ringtone."
Press the ringtone you just downloaded to set it as your default ringtone. Alternatively, you can set the ringtone for a specific person by pressing the "Contacts" icon and then by pressing the contact to whom you want to assign the ringtone. Press the "Ringtone" button and select the ringtone to set it for that person.