if you want to cover a dark circle or mark, they key is to pat the concealer on that spot, dont rub in like you would with foundation.reason being is because you want the concealer to sit on top of the spot,not rub in and blend. patting is to conceal. blending is to achieve one skintone with flawless skin. you can use a concealer brush or a clean finger. then apply your foundation of choice over it. works for me!