Actually, you don't have to study fiddle-style decorations for 100 years, or read 1,000 books or even look at 1,000,000 web sites.

Mouth music is just that. Just start doing it. Sing without words. You'll have to do it to yourself for a while as you'll feel self conscious and won't be sure if you're good enough to carry it off. When this feeling goes away, do it in public. Your style will be your style and, if you do it well, people will enjoy it.

:-)
Ian