Some graduate programs ask for a writing sample (not all do). If you need to submit one, you want to make sure it showcases your abilities as a writer, researcher, and thinker. It should be recent (not from your first year), substantial (a final paper, not a small two-page assignment), and on topic (not a paper on English literature if you’re applying to psychology programs). Most importantly, it must be perfect: smart and error-free. Even if you got an A on it, reread and revise it, ask your professor for critical feedback, and send it to the Writing Center.