Choosing the right eyeliner depends on your natural characteristics. Eye color and eye shape both play a part in what kind of liner you should use and in how you should apply it. A dark brown eyeliner is usually the most flattering for brown eyes, and a light brown eyeliner is the best for green eyes. Many colors work well with blue eyes, including browns, grays and even dark blues. Apply eyeliner to the entire length of your upper eyelid, unless your eyes are especially round or close together. In this case, you might want to line only the outside corners [source: Cover Girl].
Apply eyeliner as close as you can to where your eyelashes and your eyelids meet. Using one hand to pull your skin tight, start near the inner corner of your eye and work your way to the outer corner. Go slowly. You are better off using many small strokes than trying to draw one continuous line across your eyelid.
Eyeliner comes as either a solid pencil or as a liquid in a small bottle. Pencils are best for a subtle look, whereas liquid liner usually appears darker on your eyes and will really make your peepers pop.
Once your lashes, liner and shadow are in place, put the finishing touches on your handiwork with a coat or two of mascara. But be careful when handling mascara -- read on to discover some common habits that can decrease the shelf life of your favorite tube.