It is up to you, the Lone Eagle, to define the contents and assemble a simple, yet professional-looking application package. The package should contain all diagrams or documents you created, a printout of all of the program code, screen shots of all user screens, output report samples, database schemas and data dictionaries, etc. Some 4GL environments provide a facility to produce source code documentation and other interesting diagrams. You may be assigned to maintain the application once it s put into operation. If so, and you know this before the end of the project, pretend that you are NOT going to be the maintainer.
Every project is a learning experience.
After you wrap up the project, spend some time reflecting on what you did, how you did it, and what you will do different in the next project. Learn from your mistakes. Keep track of how much time you spent in each development activity so that you can manage your time even better during the next project. Swallow your ego and ask your end users where there are weaknesses in your application. Then soar on to the next project.