A support team wants Claude to generate replies to customer emails in a very specific style: a warm greeting, a two-sentence apology, and a bulleted list of next steps. Their current prompt describes this style in prose, but Claude's outputs vary widely in structure and tone from one email to the next. The team does not want to change models and has confirmed the task is well-suited to Claude. What is the most effective prompt engineering technique to make the output format and tone consistent?