Whatever you use, a stick-type lip color, a cream in a pot or a lipstick pencil, learn to use a lip brush.
Don’t be too concerned about changing the shape of your mouth; if it’s too big or too small you can go over or under the natural line very slightly.
Steady your hand by resting your curled fingers on your chin, then draw carefully. Fill in with color but don’t make a hard outline of a different color around your mouth; it looks very strange when the middle wears away.
* Powder lightly around your mouth before making up, it minimizes “bleeding.”