Essays can range from being five paragraphs to twenty pages or more, covering any topic, whether it's what you learned from your dog, or why societies become hierarchies. What all essays have in common, however, is that they must stay true to the roots of the word "essay" which derives from the French infinitive essayer, meaning "to try" or "to attempt". An essay is essentially your attempt to explain your point of view, and a skillfully written essay is clear, illuminating and informative. 重点：essay 要解释你的观点、清楚、易懂以及提供许多事实跟例子。
1. Define the context. If the essay is assigned, certain parameters will usually be defined for you, such as the length of the essay, format of the title page, and the intended audience (e.g. your teacher, an admissions committee). Otherwise, you need to determine your intended audience, how the essay is going to be presented to them (published in a book or magazine? through a blog?), and what length is appropriate. No matter what, if you're given directions, follow them. A brilliant essay might still fail to get its point across if it doesn't follow the rules. 反正我们就是考托福！
Choose a topic. Often this will be decided for you, but if not, try to choose something you're interested in or, better yet, passionate about. It will make the essay easier to write. You can also think of your thesis statement at this point, but it shouldn't be set in stone since it may be elaborated or changed as you do your research in the next step. A thesis statement is what your essay is attempting to explain and prove. You can brainstorm a few different thesis statements and use them to guide your research. Some examples:
o I deserve this scholarship because I am going to give back to the community.
o Crop failure is directly caused by lack of fertility in soils, not by drought.
o Making people take tests before they're allowed to keep pets would benefit society in many ways....