Here, we'll darken the lines of the face. Keep in mind that you will eventually color it in.
Darken only the lines that need to be thicker.
Avoid darkening everything.
Likewise, you must not add shadows or contrast, since they will be added afterwards with watercolor.
Start by darkening the top of the eye, then slightly darken the nose and the outline of the mouth.
You will see that we're mostly darkening intersections and outlines.
Next, do the ears and the hair.
Finish all the outlines, points, and intersections. Then we'll move on to the final and most difficult part: watercoloring.