Have you ever wondered what a Band 9 answer sounds like? Well, IELTS have published an example. Notice that to get Band 9, you DO NOT need to completely avoid hesitating and self-correcting. That would be unnatural. This candidate hesitates sometimes, but she does this because she is trying to think of ideas, not how to express them in English. So she still gets a very high score for Fluency and Coherence.