By use:
This is common for brands offering products across several beauty regimens—such as products for the face, body, hair, hands, feet, etc. of other systems, such as benefit or key ingredient.
By efficacy:
Extra Strength, Professional Grade, Plus, Pro-Level and other such terms feature a product with a more potent formulation or efficacy. This adds an additional level of complexity to your brand architecture.
By size:
Unique sizes and product dispensing features are also a great way to extend life and create value for hero products.