Are there guidelines for how to explain things?

Giving explanations is something that we all do. For the purposes of the discussion here, I would distinguish explaining from teaching by the time frame. An explanation is something that is given in one session while teaching is done over a longer period of time. Giving explanations is only one part of teaching.

Has anyone compiled rules for how to give explanations? For example, is it best to explain things from bottom up or first give an overview. Is it best to give an example first or give a rule followed by examples? If the choice varies with the situation, what determines which strategy to choose?

We have been giving explanations for as long as we have been humans. If there are books on child rearing, which we have been doing since before we were human, it would seem that there should be guides on how to best explain things.