Clear and to the Point Yud Tes Iyar, 5776
When teaching Torah in public, the subject material should be presented clearly and concisely, enabling the listener to receive it easily and drawing him to listen to what is being studied.
True, teaching in such a way necessitates hard work and much preparation, [preparing the material] once, twice, and a third time. However, then and only then will the study produce the desired benefits with Hashem's help, and the teacher is then performing the work of Hashem faithfully.
Igros Kodesh of the Frierdiker Rebbe, Vol. 3, p. 110