A white canopy rather than colored is a solid investment. Take a look at the window displays in local malls and shops. Many are done by professionals, you will come away with plenty of inspiration. Shows can become extremely crowded, if your items are not visible to the person in the back of the crowd, you may lose a sale. Don't just place your items flat on a table, get them up where everyone can see them.
Scent creates atmosphere and attracts attention.
On the other hand, some people are allergic. Holiday music in a booth selling holiday items - what could be better to get shoppers in a festive mood. But, if there is live music being performed, and music in other booths, it might just sound noisy. Depends on the show, and the booth location. Good lighting is essential.