In your business, you sell your personal services. You interpreted the prospect's needs. You determine what is required to fulfill that need.
You have to get to know the buyer to recognize the buyers' requirements and needs. You have to build a long and lasting relationship to be of any real service. The formation of such relationships require you to select prospects and ultimately clients with which you feel comfortable. If you don't, you're wasting your time and effort (in addition to your expectations for future profits) because the relationship will not live up to its full potential.
The signed contract is a consent to create a concept that (hopefully) you will fulfill. Buyer satisfaction is subjective. You have to be sure that you select prospects that you think can see benefits from using you. To ensure that the buyer sees and appreciates the benefits of your talent, you have to sell continually and reassure the buyer at all times before, during, and after what was ordered is complete and delivered.
Having fun in your workplace and enjoying creating what you are selling enables you to provide the best for your clients. You must select (if possible) only clients that allow you to operate in an enjoyable stress free environment.