Google+ offers incredible resources for video conferencing and online hangouts. Why not offer one hour lessons by video online? People can sign up on your website and access live tutorials and lesson, possibly followed by some Q and A for added interactivity.
You don't have to charge much, and as the word spreads you could end up with thousands of students attending each lesson.
If you're already a teacher, a good way to start would be to offer an additional, free online lesson in addition to the classes you take. Use this to discover what works best and what learners find useful. Once you're established, start charging and grow your classes into profitable sizes
