I darken my foundation ever so slightly by adding two drops onto the back of my hand and mixing with the foundation. I apply this all over my face and blend as usual. I then take the lightening drops and mix them in with a creamy concealer on the back of my hand to create a creamy highlight shade. Using the same technique, I take the darkening drops to create a creamy contour shade. I apply the highlight/contour and blend as I usually would. I'm loving this method over the colder months as it gives a matte, sleek look - without the extra shimmer and glittery bits that highlight/contour products are usually packed with.