The judging of the designers work is extremely subjective. Each person that sees the design will make their judgement based upon personal preferences for design styles and flower choices. There is no set of common criteria used in making decisions about whether a person likes or dislikes a floral arrangement. In fact, there is not a standard criteria list which is used by everyone. To further convolute matters, judging actually comes from more than just one or two people _ they come from the recipient, the customer who placed the order, and third party observers (anyone else who sees the arrangement). Therefore it is virtually impossible to please everyone with each design that is created.
There are three types of flower designers _ designers that create arrangements based upon following floral design recipes which others originally created, those who create custom_made flower designs for each order, and those that can do both. It is not a given that the judgement will be good for each of these types of designers. However, the judging really comes down to whether or not the resulting design is liked by the customer and fits with their preferences. Since each type can receive positive feedback on their designs, it really doesn't matter which one to choose to become. It will come down to how much creativity and artistic license one prefers to exercise as the same excellent customer service skills are required for each type.