copy .mp3 and .flac files on iPhone
I have several mp3 files that I would like to copy on the iPhone, and use some as ringtones. Apparently my "iTunes Store" app won't let me do anything of that kind. Cable connection with the PC does not work either. I even tried sending some files by email and have them play, but they don't appear anywhere else, only as message attachments.
What is the easiest way to proceed?
Thanks
iPhone 5c