For example, ‘Waiting For Godot’ by Samual Beckett has only one set, which features just a bare tree in the background – you can see the set here. The overall message of the play is that nothing happens, and yet we spend our lives waiting for something to happen. The emptiness of this set reflects this ‘nothingness’ perfectly. If you feel that you don’t need much to communicate the overall message of your play, then don’t feel you have to incorporate lots of set pieces for the sake of it.