Lip liner should not be skipped. Women need it to help the lipstick attach to the lips better. Your lipstick will never slide and slip if you use liner before applying lipstick. Besides, lip liner should be used not only to outline your lips. You can cover your whole lips with the liner first and only then put on the lipstick. Then, even after eating foods and drinking beverages your lips will look great since there will not be any visible ring on the edges of your lips. Fill out all of your lips and make your lipstick more resistant!