The Milk Makeup Flex Foundation Stick in Golden Deep is a versatile product that Catherine uses as a contour. She demonstrates how the shade perfectly matches her golden olive undertones. Catherine applies the foundation stick directly to her face and blends it in with a damp beauty blender. The result is a flawless finish that doesn't appear muddy. Catherine is impressed with the final product, describing it as amazing. Overall, the Flex Foundation Stick seems to be a reliable option for achieving a natural-looking contour.