A lot of forethought goes into the objects that accompany actors on a stage or screen. Props are the physical items used in stage, film and television productions. They are so named for being "property" of the drama department. There are many different ways to use props in drama. The writer may decide to write each prop into the action of the play to heighten a scene or add dramatic tension. Or, a director may want to position a prop in a certain place on the stage, or in the camera frame. Even actors use props for effect when performing, or to add nuance to a character.
Use the correct prop for the situation. Props can be used symbolically or to represent real actions. For example, almost everyone knows what the function of a gun is. That gun can be used to shoot someone, which has broad and severe consequences. Or, the gun could be seen and not used. Its very presence could symbolise danger, violence or a "ticking clock," whereby the audience is waiting to learn what will happen with the gun.
Time the usage of the props. The point the prop is introduced in the show is just as important as how it is used. For example, introducing a gun early in the show baits the audience. They will be hooked into the storyline and expect the gun to be used. This interest will only last for so long, however, and if the gun is not used, and not seen for a while, the audience might forget about it. On the other hand, if a gun is introduced late in the show it could heighten the tension of the climax.
Sell the story or character with props as an aid. Props can be especially useful to an actor. Handling an object during a scene can give the actor something to do with his hands while further revealing aspects of his character. For example, in the movie, "Taxi Driver," Robert DeNiro's character is alone in his room and handles a gun repeatedly. He practices drawing and aiming it at himself in the mirror. He does not fire the gun in the scene. The gun is used to help "sell" the tension in the story, foreshadow its use later in the movie and further reveal how unstable the character is.