Final answer:
Headrest covers and neck strips need to be changed for each individual client to maintain hygiene and prevent cross-contamination in salon settings.
Step-by-step explanation:
Headrest covers and neck strips must be changed for each individual client in a salon or barbershop setting. This practice is crucial for maintaining hygiene and preventing the spread of germs and infections among clients. The change of these disposable items ensures that each client receives a fresh, clean set up, thus adhering to health regulations and industry standards for sanitation.