Quick, effective tips:
- Answer the question / prompt directly (usually provided in the application - super important!)
- Talk about a topic you care about
- Show them your personality
- Write freely then go back and discover what you want to say and create an outline (see below)
- Add to your overall application - avoid as much as possible being redundant, such as covering the same information that was shared elsewhere - the essay is precious space, use it well!
- Start early
- Edit and proofread
- Have fun and use it as an opportunity to self-discover
- Be honest!
You can think about the essay as a way to share more about yourself qualitatively, while more quantitively elsewhere in your application (GPA, SAT scores, etc). You're not just writing to an admissions committee, you're writing to humans who have families, hobbies, successes, personal challenges, and feelings.
But first you're writing to yourself. What do you want to say to yourself? What do you want to discover? What is one thing that matters to you? What was not covered elsewhere in your application that you would like to now share? What has been one of your greatest life challenges? What do you consider to be one of your greatest successes? What are you most passionate about?
Write eight to ten different endings to each of these questions, just write and don't judge what you are writing down (this is sentence completion).
Do this for a week, and then go back and see if there are any patterns or words/topics that come up regularly.
Next write for fifteen to twenty minutes (or more) on those that you want to explore.
Do these... and you'll have a good start!