What should a barber ensure before starting any treatment on a client?

Before starting any treatment on a client, it is essential for a barber to ensure that the client’s scalp is clean. A clean scalp is critical for several reasons: it promotes hygiene, prevents potential skin irritations or infections, and ensures that any products used during the treatment can work effectively. When the scalp is clean, it allows for a more even application of products and better results from the service, whether it be a haircut, shave, or scalp treatment.

While other factors like a client's punctuality or identification might be relevant to the overall experience at the barber shop, they do not directly impact the immediate safety and effectiveness of the treatment being performed. Caffeine consumption may be a personal consideration but doesn’t have a direct correlation with the quality of the service. Therefore, focusing on ensuring the client's scalp is clean aligns directly with maintaining professional standards in barbering practice and prioritizing client care.