Tie your closing paragraph to your introductory paragraph by repeating some of the original imagery or information from the opening statement. It is important to think of the opening and closing paragraphs as bookends, which frame all of the content in between.
Develop meaningful conclusions that detail the value you have gained in your own experiences. Use what you have learned about yourself and your intended field to detail your intentions for your future goals.
Show enthusiasm about the chance to be accepted into the program for which you are applying. Make sure not to write with the assumption of actually being accepted. A good example would be, "I look forward to the opportunity to discuss my interest in your program in person."
Keep it short, about four to five sentences is adequate. It is important to stay focused and not to add any new information in the closing paragraph.