The one thing we find common among successful applicants is that they are able to show how they think. These applicants write about why they did what they did.
When you get down to writing your essays keep these tips in mind that can go a long way in projecting your thought process to the admissions committees.
Motivation behind pursuing an activity.
Why did you make that career shift, why did you volunteer for that cause, what motivated you to pursue that hobby for that long? Making a mention of your motivation to pursue these initiatives would make more sense if you can show that (a) the decision was a step in achieving a bigger objective, or (b) it benefited you in other indirect ways like improving presentation, interpersonal or team skills.
Rationale behind an important decision.
"My friend lost the election by a single vote - my vote - which went to the better candidate." -- this applicant did not want personal relations coming in the way of his commitment to bring dynamism in the committee. He also honestly confessed to his friend without affecting their relationship.
Such a story can convey a lot about your values and attitudes to the admissions committee.
Process of mental transformation.
The process of changing your beliefs can be painful. How you handled the pain can project your attitude when the chips are down. At times the change can be sudden as when a new logic strikes like lightening. Circumstances that led to flashing of the idea can show your conduct in everyday situations which may have led to your being the person you are.
How a new idea emerged.
New ideas emerge from a dynamic interplay of learning across different disciplines. People who passionately pursue and learn from activities at work and in personal and community involvements are likely to be more creative than those whose involvement is confined only to things at work. Narrating the circumstances that led to the development of a new idea shows you as some one who understands how new ideas emerge.
Use the above tips to identify stories for your application essays.