When you just can't paint well no matter what you try...

When you can't get decent symmetry between the left and right, try painting a grid. If you paint it using a very pale beige, it won't be noticeable at all once you remove it.
If you feel the paint is just too thick, try adding a little bit of thinner to the color. If you're finding your strokes are watery and inconsistent, use a tissue or something similar to control the amount of paint on the brush.

Step 1

First of all, mock up the eyes using a brown color diluted with water. If you make a mistake, wipe it off using a thin cotton tip or tissue dipped in thinner. As the color is a very pale brown, it will not be noticeable once removed, and is kind to the skin.

Step 2

Using white, paint in the whites of the eyes, and paint the iris part of the eye in whatever color you like.

Step 3

Use a dark color to add shading to the eyes. Rather than painting it all completely dark in one go, try using diluted paint to paint it a little at a time.

Step 4

Using black or a dark brown, paint in the eyebrows and the main lines of the eyes, and insert gradating shadows in the whites of the eyes.

Step 5

Paint in the irises of the eyes. Try painting it to give a gradated feel.

Step 6

Paint the outlines of the lips using a fairly strong color, and then paint the lips using a slightly lighter color. Create a lip color that you like based on the image you're after, such as pink, red or orange.

Finished!

Last of all, add highlights (sparkles) to the eyes using white. Be careful not to make these symmetrical between left and right!