Many people use the term "feng shui" very loosely, but as a verb the implication is to do something which can change a space to attract more business to the vendor. Even though you can not do the same, in any traditional sense, with something like a car, you can actually assess an Arts and Crafts booth, if certain things are under your control.
For example, if a booth is going to be inside a convention center or some indoor environment, the booth will be like a work cubicle, where it is part of the "bigger picture." I once had a client doing shows at the Santa Monica Civic Auditorium and it was easy to identify the better parts of the building with a floor plan readily available to divide into direct sectors. Looking up when the building was built is also just a click away on the tax assessor's website.
Once you have identified the best part of the building, there may or may not be a way to address the area with elemental remedies, but just being in the better part of a building can give someone a "leg up" or advantage in comparison to other vendors.
Of course, there is also some environmental psychology at play, as some people like to be right near the door and others notice more business when placed near food vendors or bathrooms. This is strictly about visibility and sometimes that alone can help you do better as a vendor.
For outdoor venues, there is no flying star chart to consider. This is the energy field that gets captured inside a building. But there can be some outside cues in terms of how the qi flows best. This is where a feng shui consultant would try to determine the best qi flow arrangement, with the aisles between booths being much like virtual roads. Yin-Yang Theory would also come into play and this includes a lot of things that are common sense, like not being in a dark, dingy area.
With the actual booth lay-out, there are some design tricks which many season sellers are already aware of. These are things you can do to lure people towards your booth and to stay longer. Often, a long table is set up at the "facing" side of the booth and items for sale are right at the edge of the booth perimeter. There is nothing wrong with this arrangement. But by creating a U-shape where the facing side of the booth is open, it requires that potential customers come into the booth area, literally, in order to see the items for sale on display deeper into the booth. This allows the seller to engage in conversation easier with the customer. This alone can increase potential sales.