Write generic test plans and test cases, which focuses on the intent of the requirement rather than its exact details
To understand the scope of change, work closely with the product owners or business analyst
Make sure team understand the risks involved in changing requirements especially at the end of the sprint
Until the feature is stable, and the requirements are finalized, it is best to wait if you are going to automate the feature
Changes can be kept to a minimum by negotiating or implement the changes in the next sprint