If you provide the desired items, you will make sales. For Halloween our customers are mostly interested in novelty-type candies, cookies or cakes. Best seller is the Pretzel Rod. Then add one of Wilton's new handmade Halloween novelty molded chocolates you've made. Glue mold candies on with melted chocolate.
Cookies sell well.
Best seller is a Jack '0 Lantern shape. These don't keep long. Easy if you first ice cake white, then just add a top-coat of preferred colors. Spread smooth with metal cake spatula. Not much difference, just brand names.