Which of the following practices is essential for cleanliness in beauty practices?

Storing powder in a clean shaker is vital for maintaining cleanliness in beauty practices because it prevents contamination and ensures that the products being applied to clients are safe and hygienic. A clean shaker means that there is no residue from previous uses that could compromise the integrity of the powder, which is especially important when working with clients who may have sensitive skin or allergies. Hygiene practices are crucial in beauty settings to promote health and safety, and proper storage alone can significantly reduce the risk of contamination.

Other options compromise cleanliness by introducing potential hazards. Using old towels can transfer bacteria and dirt, while reusing instruments without cleaning can lead to infections. Expired disinfectants lose their effectiveness and may not kill harmful pathogens, increasing the risk to clients. Thus, proper practices like storing powder in a clean shaker uphold safety and professional standards in beauty practices.