Using the ETUDE 2X Tinting Eyeliner is easy. First, make sure your eyelids are clean and dry. Hold the eyeliner pen like a pencil and gently draw a line along your lash line. You can start thin at the inner corner of your eye and gradually make it thicker towards the outer corner for a more dramatic effect. For a more natural look, apply a thin line all along the lash line. When you're done applying, let it dry for a few seconds to prevent smudging. Keep in mind that if your eyes are sensitive, test the eyeliner on a small area of your eyelid first. To maintain the eyeliner's quality, store it in a cool, dry place. Avoid exposing it to extreme heat or cold, as this can affect the consistency of the formula. If the tip gets dry, you can gently press it on a piece of paper to get the product flowing again.