Do Your Own Research
Before you market anything to your audience,
you have to thoroughly do the research.
When you are promoting a product, a class, or provide any type of service, make sure that you are knowledgeable about it.
I always say that I'm a student of my craft because I'm always learning and staying up-to-date with what's new on the scene.
Same with you, be a student of your craft and always always always do your own research.