Flooring element I believe is one of the most under valued element in a booth design. An excellent booth design not only has to consider the visual elements of the structure, but also take in the consideration of all the other senses. A proper booth design must consider the fact that it is not a one-dimensional interaction, but an immersive experience.
Flooring can add the needed texture and at times could provides necessary reflective surface for lighting.
I have seen designer that uses vertical structures (walls, partitions, drapes, etc), to create clear define space for the space. The vertical structures creates a visual disconnect between attendees and the products. Instead consider flooring treatments that could define the space without building a fence around the space.