Grouping
In addition to their dialogue and mannerisms actors relative positions can reinforce their relationship to each other.
Add interest to the scene by having actors adopt different stances and relative positions: standing, leaning, sitting, walking, etc. You must still keep in mind if the action is appropriate to the character and the situation. Avoid giving too much prominence to less important characters, the most important person is usually the one currently speaking and they must be clearly seen and heard. This does not necessarily mean keeping them at the downstage area of the stage, if they have to relate to another actor who is further upstage it may require them to turn their back on the audience, making them less prominent and literally upstaging them.
Isolation

To indicate remoteness, unpopularity or high office isolate one actor from the others. This
actor could be at the farthest point of the stage from the main group, or the group itself could be
tightly bunched together.
Friendship

At the other extreme, to signify friendship place the actors close in an open stance, i.e. they
stand (or sit) at about 90° to each other, with no apparent barrier between them.
copyright Leigh Graham 1997-2010.