This is a great question. OK, it might not be a question but when I asked for ideas on Facebook, I just asked for topics. Still it is a great question.
Let's assume you have an agent you really want to work with. The same goes for an editor that you want to work with. You have submitted to this person and that editor/agent passed on that first project. Now what? You really thought that first project was great and you really want to work with this person. How do you go back?
The first thing I would say is to go back to that rejection letter. There is a hope that the person sent some sort of feedback other than, I am passing. Before you even think about firing off that next project, take the time to really look over those comments. Then, take the time to really examine your project with an objective eye, and see what you did. Now, look at the new project.
The odds are, you are probably making the same mistakes you did on project number 1. I have several authors who continually submit stories to me, and continually, I reject the stories for the same reasons. These people have not learned.
Now, let's assume that you did go back to that new project. The hope is that you took those revision comments and, as you wrote project #2 you incorporated those ideas into the story. That is what we are looking for, especially if we send you a lot of notes. We apparently liked something you did in the first project to see something and to send you comments. Now, can you do something with those comments.
As you write that new query letter, here is what we want to see in the letter.
First, remind us that you looked at an earlier project and passed on it. It is OK if you tell us why we passed on that project. We are going to use this to your advantage. As you tell us about the new project, take the time to highlight the things you did in this project that remedied the things we did not like in the first one. When my authors send in revisions for their current works, they always take the time to show exactly how they met the needs of the editor. You should do the same thing.
Now, let's take this to a new level. Let's assume you have now sent in three projects to that same person and are getting the same feedback. This can mean one of two things. Either you are not able to take the criticism and make those changes; or you are being told politely that this is not the place for you. The odds, however, is that it is the first issue.
We have no problem if you come to us with a new project. We are always looking. But please remember, if you continue to do what you were doing, and it is failing, you will continue to fail.