A resume writer once suggested carefully analyzing a company's job ad and the position description. Underline key words--Jargon, descriptives, ect. Then be sure to use those words in your resume and cover letter. For example-- the ad said something about improving patient outcomes. Make sure your objective statement says something about wanting to improve patient outcomes.
Now apply this to your application goal statement! Carefully analyze the schools website and literature--examine the program description, mission statement, outcomes expected. Notice the descriptive words, jargon they use and be sure to use those words in your statement.
Of course, be sincere about what you want and why you want to do what you want to do. Then apply the above method for grammar and pizzaz. The admission committee can detect fakes and insincerity and they will probably vomit if you write about how nursing is "a calling" and how you "want to help people", so avoid that too.
My nursing school statement was pretty much outlined by the school's requirements. I had to state what program I wanted to apply to, purpose in applying for graduate study, my future professional plans, describe what I have done to develop a realistic picture of the practice role I have chosen and any additional information which may be useful in evaluating me for graduate study, including working with underserved populations.