I would just work with someone to compose it, depending on your age and where you are in school. I'm one of those word geeks that enjoy writing (both academically and otherwise), therefore I've aided relatives and friends in this endeavor.
So, based on my personal experience If I am writing my essay:
A.) Someone has a fantastic essay concept and a strong point of view. They simply don't know how to phrase it or lack the patience to do it alone.
B.) The topic on which they must write is uninteresting, abstract, or overly specific. You can make any subject interesting to write about, but there are occasions when you need to dive deep.