Thanks, all. I might take that advice about just pouring out everything then paring down what's on paper to effect something that resembles an answer to the topic ("Why do you want to be an optometrist?"). Usually, this essay is about a thousand words, is that right? (I'd like not to have to write several versions of varying length for the different colleges to which I end up applying.)
Actually, these were the limits for the schools I applied to:
(I just loaded my saved docs, I could be wrong...)
ICO- 500 words
Berkeley- 5000 characters
NECO and PCO- no stated limits.
Personally, 500 words and 5000 characters (2 separate essays, so more like 10,000 characters) was a huge difference, so I would try to find out the word count for the schools you're interested in before completing the entire essay. This is because I was extremely concise for the ICO essay, whereas the essays I wrote for NECO and PCO were anecdotal and much more detailed.
This is, of course, before the centralized apps. came about, I'm not sure how the application essays would work now.
I didn't exactly know how to start my essays either. However, I wrote down all the points I wanted to make in regards to the question, then ranked them in importance. Then I made connections between them, and dropped the points that were less important depending on the word limit.
Good luck