Yes. It's called transferred learning and it is legal and ethical.

Personally I have done so successfully in IM to the benefit of thousands of IMers.

The fact is you don't have to have the whole "100 years experience gold wrist watch" (and "screenshots") before you can help others achieve something positive in their own lives. It helps though to at least be "doing" as you are "teaching" and to be HONEST and UPFRONT about it all....