Final answer:
A professional should have a consultation with their client prior to a waxing service.
Step-by-step explanation:
A professional should have a consultation with their client prior to a waxing service to ensure predictable results. During the consultation, the professional can discuss the client's desired outcome, any allergies or sensitivities, and any specific concerns or preferences. This helps the professional tailor the waxing service to the client's needs and reduces the risk of any adverse reactions or dissatisfaction.