To use face primer effectively, start with clean and moisturized skin. Begin by dispensing a small amount of primer, typically a pea-sized dab, onto your fingertips. Gently apply the primer evenly across your face, focusing on areas with enlarged pores, fine lines, or uneven texture. Use upward and outward motions, ensuring it's well-blended into your skin. Allow a minute or two for the primer to set before applying foundation or any other makeup products.