In addition to skin type, what other client factor is essential to consider before performing services?

Considering a client's history of allergies is essential before performing any services because it directly impacts their safety and well-being. Allergies can lead to severe reactions when certain products or chemicals are applied to the skin or hair. By being aware of a client's allergies, a barber can avoid using products that might trigger an allergic reaction, which could range from mild irritation to serious health risks.

In addition to avoiding harmful reactions, understanding a client’s allergy history helps in building trust and demonstrates a commitment to their health and comfort. This client-centered approach enhances the overall service experience and promotes a safe environment for both the barber and the client.

While other factors, such as a client's age or favorite hairstyle, may influence service choices and techniques, they do not carry the same immediacy in terms of health and safety as understanding allergies does. The time of day is generally not a factor that would influence the choice of services in terms of safety and appropriateness for the client.