To make your lips look thinner and smaller, hide your natural lip line with concealer. Line the lips just inside your natural lip line. Smudge the lip-liner onto your lips to soften the line. Apply your lipstick onto the lips keeping the colour inside the new lip line created with the liner. This will create the illusion of thinner lips. Using a darker lip liner and lip stick without shine or shimmer will also make the lips look thinner and smaller.