A stage set is required in most cases in the theatre arts. It provides a creative space and supports the three main elements of the theatre: actors, the audience and the text. As a result of the act of stage design, the set visualizes various dramatic effects. This feature of the stage design distinguishes the theatre arts from other art forms, including painting, sculptor, and music. Those art forms besides the theatre arts are created mainly to express the artist’s inspiration, rather than to be presented for an audience. For example, it can be hard to say that Vincent van Gogh created his paintings solely to display his work at exhibitions. On the other hand, stage artworks are created for the audience. If a stage set were poorly understood, then the work would not be a highly functional product. The purpose of stage design is to give information on the story to the audience visually on stage, whether inside or outdoor. From this point of view, we can generalize the concept of set design and compare it with general product design. Although it is difficult to draw a simple comparison between product design and set design, there are similarities and differences between the two designs. In both areas, a good design is effectively visualizes its functions to its users, or audiences in the theatre. The main difference is that artistic expressions are emphasized in set design, while practical functions are more important in product design. For example, a product designer creates a design considering market environment as well as the target users to fulfill expected capacities for the product. In this sense, set design can also suggest practical solutions to some problems in the production, when the script is considered as a product. The set designer can apply the methodologies of general design in the set design process, and this will be beneficial to express his/her ideas. In this paper, I discuss design methodologies, design process, and application of the design methods. As design methodology is quite a broad and general area where a number of scholars research and take various approaches, I focus on stage design, and how general design methods can be applied in creative stage design.