There is nothing required in implementing the ETA. All artistic activities require something else more, but not ETA.
Art therapy requires materials and techniques to engage in artistic activities. To paint, you need at least paints, and to play music, you need an instrument. In addition, you need to be able to draw and play musical instruments.
No material tools or techniques are required to implement ETA. Only, if there’s space, it is enough. With a play director, ETA can begin.
All discussions and practices are conducted the director. Therefore, a director who can lead the discussion, write, and have an eye for excellent performances is critical for a successful ETA process.