Keep the following tips in mind when submitting your statement.
Tips for Submitting a Statement of Interest
Tell a story about yourself, your interest in the subject, and what you would contribute to the class. Don't focus on what you think the professor wants to read; faculty look for students with diverse backgrounds and attitudes. The more the instructor can understand your motivations and approach, the more likely he or she will keep you in mind for the final class list.
Save your statements as you write, and be aware of deadlines. Your submission will not be accepted after the quarterly deadline.
Keep an eye out for seminar-specific questions and be sure to answer them regardless of how you rank the seminar.
Share your statements with an advisor, family member, or friend—they can help proofread.