The hand-held fakery of drama. Every penny spent on props is immediately seen onstage and makes a noticeably finer production.
The painted back-drops and flowing drapes. They store in a very small package, but fill an immense amount of the stage picture.
Scenery is most cost effective when it is re-used and rented to others. The cheapest way to store it ( because it is usually quite large ) is on rented freight trailers.
If you see an item in a play move by itself, twirl around, buzz, flip or unfold It is likely one of these gizmos performing the trick.