What is a common sign that a client may need a trim?

Visible split ends are a clear indicator that a client may need a trim. Split ends occur when the hair shaft becomes damaged and frayed, often due to environmental factors, heat styling, or lack of proper care. When the tips of the hair split, it can lead to further damage if not addressed, as the split can travel up the hair shaft. Regular trimming helps to remove these split ends, maintain the health of the hair, and allow for better styling.

The other options do not necessarily indicate the need for a trim. Extreme shine in hair color is more related to the hair's health and the quality of the products used, while increased volume may suggest healthy hair growth. Darkening of hair fibers could be associated with color treatments or changes in the hair's condition, but does not indicate a need for trimming as split ends do.