Sandy,
I wrote the essay like it was a standard 3-subject essay with an introduction and conclusion. For example, on the practice essay I had 3 examples of how opportunities can be disguised as difficult situations, and each example had its own paragraph. Then I had an introduction paragraph (with thesis sentence and all that) and conclusion paragraph. I just barely had enough time to brainstorm examples, write, and re-read before time was up. I filled up all of the available space on the page they gave me.
I'm sure there are other ways to go about writing the essay, but this was just the way I was most comfortable doing it.
Shannon