Actors should also gesture with the arm closest to the back of the stage so that they are less tempted to turn away from the audience. Positioning actors in a straight line across the stage isn't advisable since characters in a line tend to bend forward to see each other and, after all, we rarely see a group of real people standing in a line when speaking to each other. Characters placed in triangle formations look better on stage and are easily seen by the audience. The actors should also pay attention to who is speaking. While one actor is talking, others on stage need to be careful not to distract by unnecessary movement.
Movement motivated by what is being said is acceptable.
For example, actors in a crowd who are listening to a speaker may nod and look at each other to show how they are responding. If a crowd gets so active that the movement of the actors distracts from the lines being spoken, though, then that action is inappropriate. Even rehearsing for something as exciting as a play can become dull with all the necessary repetition. To relieve the tedium and pressure of practice, intersperse rehearsals with set-making days. For scenery, stretch another row of sheets or craft paper at the back of the stage and paint the scenery directly onto these or use the natural setting of your yard.