Learn more about the art of essay writing. Take a class, read books and check out different Internet sources. Read about a number of notable writers and how they go about writing their pieces.
Always start early. Starting a week in advance is sufficient. Starting a few days before the deadline can still result in a pretty good article. Never wait until the day before the deadline to complete the essay. There are some people who can churn out articles even with a deadline looming, but most likely, they are either writing about a topic they have mastered or their writing skills are at a high level.
Prepare careful and thorough research. Search all relevant articles via the Internet and collect all books related to your subject. Keep all in one place so time won't be wasted locating them. Scan through all your references and revert back to those that have something to contribute to your essay.
Plan how you will go about writing your essay. Determine all the important points in your essay and their supporting arguments. Arrange these points according to how you wish to present them, like in order of importance or in chronological order. Determine how you can expand upon these points.
Edit your article. Even if you have foolproof arguments and rock solid evidence to support them, all the effort will go to waste if your professor sees a spelling or grammar mistake. After writing your essay for the first time, take a break before looking the whole thing over. Check if there are any spelling or grammar mistakes. Determine if your sentences are too wordy. If you still have some time, review again until you feel your essay is perfect.
Upon completion and receiving your grade, consult with your professor, especially if you feel that you have gotten a lower grade then you deserve. Find out the weak points of your essay and ask your professor what could have been done differently to receive a higher grade. This constructive feedback will only help the next time you write an essay.