Essay 1
What do you hope to gain from The Duke MBA?  How does it fit into your short- and long- term goals?

This is standard goal essay – the heart of your application. Conciseness will be critical virtue provided you have to cover a lot of ground here. Structure your response by quickly describing your past experiences, introducing your short-term and long-term goals, clearly establishing a gap that according to you only Fuqua MBA can bridge. Also, it’s crucial to relate your expectations to school’s unique resources – curriculum, clubs, and special programs. Attempt to write a paragraph with each sentence containing something unique about Duke.

Essay 2
How will you contribute to the overall experience of your peers at The Duke MBA? 

Given that you must have addressed most of your professional stories in the previous essay, provide the reader peek into other dimensions of your candidacy – extracurricular / community involvement accomplishments, unique background, and any other standout experiences. While you may think of multiple stand alone stories, it will be equally important to apply an overall theme to this prompt and also explain how exactly your accomplishments will turn out to be beneficial for student body at Duke.

Essay 3
Discuss a person, event or experience that has significantly shaped your life and explain why.

Pick up an interesting anecdote, a story that completely belongs to you. Structure your response in the START framework. S- Situation, T- Tasks at hand, A- Actions taken, R- Results of your actions, and T-Takeaway. Remember, the story matters only so much. What matters more is how deep adcom can look into your perspectives, your beliefs, and your values via this story. Focus on bringing out your unique dimensions that haven’t been introduced yet and make adcom feel “AHA”!!

Long Essay
Today, companies must navigate through complex and interdependent issues. They must deal with health and security matters, environmental impact questions, and diversity and cultural concerns. Leaders need adaptability, imagination, and emotional intelligence as well as business acumen.
Upon graduation, a Duke MBA will be a leader of consequence - able to deal simultaneously with complex matters and engage skillfully with colleagues, clients, and community.  What impact do you hope to have as a leader of consequence?

Given this is a long essay you get the opportunity to go in depth of the goals and objectives you mentioned in essay 1 and explore the impact you would create via the same virtue. Avoid the tendency to repeat essay 1 objectively by providing one or two level deeper insights to reinforce your clarity and passion about your goals.
This anecdote is completely forward looking but you may use some space to introduce unique aspects of your past experiences and impact your created, exploring how being leader of consequence already applies to you in your small little world. While addressing the forward looking part, you will have to detail the nitty-gritty’s of your proposed career trajectory and what change will your bring there. Reading about accomplished personalities in your field of interest can be one of the ways to stimulate your thoughts further.