The biggest problem I see is that everybody is too eager to jump headfirst into the fancy stuff... all the custom made goodies, objects, fields... before they can establish a good working knowledge of the basics of the TE and learning the minimum about what is required to build a simple, stable terrain. Then when all the fancy stuff goes screwy, they have no experience to fall back on, no sense of "how it's supposed to work".
Best advice I can give someone...
Baby steps.