The leadership questions usually come in two forms: the kind that ask about your "leadership style," and the kind that ask you to discuss a "leadership situation." You should not try to use a single essay to address both questions, because they require different emphases. The first question asks you to describe principles that define your approach to leadership. You should then back these principles up with evidence of how you've applied them.
The second question wants you to focus on a single experience (or in some cases two experiences). For these essays your first objective is to flesh out the details of the situation and the contributions you made. You must tell an in-depth, engaging story before you even worry about the insights and lessons you deduce. Then, when you get to that stage, your insights into leadership should be focused on the story you just told. Don't stray too far and try to include everything you know about leadership.
After this basic difference in emphasis, the goals of both essays are essentially the same and include the following:
This applicant focuses his first six paragraphs on the details of his project and the roles he played. He includes specific duties such as the following: "My role was specific: develop a strategy to improve navigation, communicate the complete range of ADP's products and services, optimize the flow of traffic to drive leads for the business segments, persuade visitors to purchase ADP products and services online, and create a platform for ADP's evolving E-business strategy." Because he focuses on concrete examples, he does not need to tell us about his ability to strategize or communicate. We can deduce for ourselves the kinds of skills he shows in his work.
In his conclusion, the writer avoids citing generic clichés about leadership and instead focuses on practical lessons learned. There are implicit broader principles behind those lessons, but it's more important that we see how he has applied them to his specific case. For example, "the importance of matching corporate strategy to Internet strategy" speaks essentially to the importance of aligning goals, which applies to all leadership situations.
This applicant relies a little too heavily on generalized insights into leadership. He draws on one concrete example in the second paragraph, however, and this makes a great difference. The best way to demonstrate leadership ability is not to write vaguely about your success in completing projects or motivating people. Instead, name an example of a problem you faced and led the way in overcoming, or mention a person whom you earned the support of after initial difficulties. Leadership is a quality that everyone will enthusiastically claim, but few will have the proper strategy in supporting their claims.