To use this lip liner, first, make sure your lips are clean and dry. You can start outlining your lips with the liner, following your natural lip shape or creating a slightly different one. Then, fill in your lips with the liner for a more even color. Remember to keep it away from high temperatures and direct sunlight to maintain its quality. If you have sensitive lips, it's a good idea to do a small patch test first. After each use, put the cap back on tightly to prevent it from drying out.