Remember to keep in contact with your client. Optimally, every week you create a release for your client, email it to them, ask them for feedback, incorporate the feedback into your current set of open Issues. If they don't reply, it is fine.
The Beta, RC1, and 1.0 Release are just the times when we do grading. They are major releases. You should be getting feedback from your client constantly, not waiting for a major release.