Lay the mirror on a flat surface with the reflective side facing up. Use the makeup sponge to spread a small amount of liquid latex onto the mirror. Spread the latex over an area of 1/2 inch to 1 inch. Use your fingers to lightly shape a scar into the latex. A scar can be a small, slightly raised mound or flat discoloration in the skin. Keep the latex layer thin and wait for it to dry. Hold a blow dryer over the latex for faster drying time. Keep the blow dryer on a low setting.
Use a clean makeup sponge to cover the latex layer with foundation. Choose a foundation that matches the color of your skin. Heavy liquid foundations are best for concealing small inconsistencies in the latex. Add a touch of blue and black eyeshadow, to create slight discoloration. Mix red blush and black eye shadow together. Add the mixed color to the foundation applied on the latex blend until the color is slightly darker than the color of your lips.
Peel the latex off the mirror using your fingers. You can slide a knife underneath the latex for smooth removal.
Spread the spirit gum on the backside of the scar. Press the latex scar to the area of the lip you choose. Press a piece of latex outside of your lip. Hold your lip still for 3 minutes, or until the spirit gum dries completely. Blend the edges of the latex with the foundation.