Agree on the first area and the reason for it
Explain what you notice in your face at rest, from the front and in profile. Ask what difference treating one area might make and which concerns are likely to remain. Your priority may look different from different angles.
Set a review point before deciding on the next area
Ask what you should look for after the first treatment has settled. Compare photos taken in similar light and from the same distance, and discuss whether another area still matters to you.
Ask for a clear estimate
Find out what the initial stage would cost, whether a review is included, and how any later treatment would be priced. You can decide after each stage whether to proceed further.