Final answer:
Helen should use a variety of practical tools for set design, including backdrops, props, lighting, sound, stage pieces, costumes, and makeup to create a successful theatrical production.
Step-by-step explanation:
The practical tools of set design that Helen should use are key to the success of a theatrical production. These include backdrops and props, lighting and sound, stage and set pieces, as well as costumes and makeup. Each of these elements plays a vital role in bringing a play to life. Backdrops and props, for instance, make up the visual elements that support the narrative, while lighting and sound can influence the atmosphere and mood of a performance. The stage and set pieces define the physical space where actors perform, and costumes and makeup help to define character and time period. The synchronization of all these elements during the final rehearsals is what will enable the director to integrate the vision with performance, resulting in a realized production that audiences can enjoy and immerse themselves in.