Tell me about a time you were dissatisfied with your work. What could have been done to make it better?

A live example will work best here. Taking an example from the writer domain, you can modify it as per your domain.
“Being a writer, I have seen the times when the ideas came to my mind automatically with the flow of creativity and emotions. But there are also some times when you are not in a good mood to write or you want to write but didn’t get any idea about what to write. This is the thing that boss didn’t understand and even we can’t explain them, on those times I write the articles forcefully. However, those were got approved by the supervisor but I had a feeling that I could have done it better,”