Delineate Your Lips - How to draw a realistic eyes in Photoshop by Kajenna - How to draw lips correctly? The first thing to keep in mind is the shape of your lips: if they are thin or thick and if you have the M (or heart) pronounced or barely suggested.
If you love color, why leave any of them out? Use the Rainbow Method of picking a full spectrum of color and apply it as heavily or as lightly as you want.