Outlines are important for any type of writing, particularly when writing about a broad topic. It is a good practice to begin a brainstorming outline by jotting down words that describe you and your goals. Ask yourself the proverbial question "What do I want to be when I grow up?" Think about that question and how you want to fulfill your goal. Do you want to be a writer? A doctor? A lawyer? A social worker? Even if you are undecided, you can still brainstorm your academic interests. This will help you focus your essay when you begin to write.
In order to write a finely tailored statement of purpose or intent, it is advisable to research the university, college or program to which you are applying. For instance, if you are interested in marketing, see if the school has a recognized marketing program. If you are interested in political science, you could see if there is a renowned professor at the school under whose tutelage you could prosper. Try to learn as much as you can about the program or school so that when you write your essay, you can display your interest and desire to be there.
While drafting your essay, remember to whom you are writing: the people who will either accept or reject your application. You should try to write in a fashion that is formal but still pleasant. You do not necessarily want to sound completely rigid and robotic, but you also should not disregard the rules of grammar or write in a conversational tone. Further, some humor in the form of irony can be endearing, but do not be sarcastic or go out of your way to find ironies. Further, you are writing to be admitted to an educational program, so it is imperative that you run the spell-check multiple times and proofread for logical and grammatical consistency before you send in your letter of purpose or intent.
A good letter of purpose or intent will logically tie together the important qualities of the applicant and the potential advantages offered by the undergraduate program. Show that you can connect yourself to the program by saying things like: "I have always had a passion for, and excelled in, history. This program has been nationally recognized for its history department, and I believe that under the direction of its faculty, I can excel academically and thus further my goal of becoming a historian." Do not leave conclusions for inference, but instead, clearly state the logical conclusion.