This writing is not actually for theatre directors but those who come to help in rehearsals with their special skills but occupy director’s place by giving their suggestion (of course necessary ones) to actors rehearsing on stage. Though they don’t know their valuable suggestions to actors (without director’s approval) are putting performers into confusion, I’m not going to forgive them for this.
In this condition, the director must have understanding to know how his visitors are destroying their actors and his blockings for the play.
If director is not able to make the scene and if he really need suggestions from the visitors, he must ask for that but these visitors must not have the right to direct actors on floor.
Yes it happens, sometimes the director can’t think proper or better scene, and there may be shortage of time, then first he rely on his own skill then he should ask to the actors and visitors as well, but nobody should have right to direct actors apart from the director, even any actor in the group want to suggest something he should suggest to the director first, if director feels the suggestion given by actor or visitor is better and applicable, he would ask for actors to perform that way and if he finds the way is good, he would approve the scene with his works.
But don’t always think that all directors may have that understandings, some are dumb and some are morons too, yes.
How you will find that sorts of director sand their invited visitors is easy. Work with them and you will know that.