All of the following are examples of an add-on service to a basic pedicure EXCEPT?

A foot soak is generally considered a standard part of a basic pedicure rather than an add-on service. In most pedicure treatments, the foot soak is essential for softening the skin and preparing the feet for further care. It typically consists of soaking the feet in warm water, often enhanced with bath salts or essential oils to relax the client and cleanse the feet.

In contrast, foot massages, callus removal, and nail polish application are services that can be added to enhance the overall experience and offer additional benefits. These add-on services usually come with an extra charge and provide more specialized attention to the client's needs, making them distinct from the foundational elements of a basic pedicure, which would include the soak itself. Understanding the standard components of a pedicure helps differentiate between what is basic and what can be offered as an enhancement.