Begin your essay by giving a quote on character of a person or the influence of a person's behavior. then go onto the body in telling how the person is related to you.
after that, start giving examples on how the person's character has had an impact-be it positive or negative. give examples of both. make the examples quite narrative. you could give a maximum of five examples as it will be time consuming. "i really wonder what life would have been without that one person or that one incident!"-make this line as the last line of your essay.