When I teach directing to my advanced students, I start w/a simplified presentation of Alexander Dean basic elements of directing-- Composition, Picturization, Pantomimic Dramatization (business), Movement, Rhythm, and Tempo. It's not a lecture-- they
become all the models, participating in the demonstrations and doing exercises to help them understand each element and how it operates on stage.
Then they break into small groups of 3 or 4 and stage "contentless" or neutral scenes, the idea being to convey meaning using the elements they just learned about.
Then they move on to scenes from actual plays, focusing on blocking to demonstrate motivated movement and character relationships.
Then when we get to our final project for the semester, (a 45-minute one-act piece) they can request to be a student director-- I usually take all who are interested, and divide up the play into sections-- they collaborate, and then each direct their section. I serve as "consultant" and producer, and help pull it all together as we get closer to performance. Some of these nascent directors then apply to direct the Drama Club play-- which is a full-length, fully-produced piece, again w/me supervising. This year we did Fools, with three student directors, and it was fantastic. All three students had come up through the ranks and showed their interest and capabilities.