If you were to issue a warning to newer practitioners of something concerning this practice, what would it be?

I know there is a lot of unfounded fear-mongering that is not more than empty warnings. So I am not talking about that; but with everything comes a hazard, which is why I am asking if there is a warning that you could issue

It could be anything ranging from practice or subjective to mental or actual spiritual-related hazards, not necessarily a mysterious fear-mongering. Even that is "ok" if you think there is a basis.