Draw a line down from the middle of the nose (between the nostrils) to the upper lip. This line gets wider as you get towards the upper lip and you then draw it along the upper lip to the corners of the mouth.
Let the line run in circular way from the corners of the mouth across the cheeks to the nose.
Draw a white stripe on top of the lower lip and draw a black line around it for a wide effect.
If you do not want the colours to mix, be sure to wait for the first layer to dry before applying another colour over it or up against it.
Hint: Regularly change the water you rinse your brushes in and preferably work with two water bowls: one for light and one for dark shades.