Provide each child a sheet of blank paper along with pencils and coloring items like crayons or markers. If you don't want to risk the children getting ahead, only provide pencils until you are ready to have them start coloring.
Have the children look at their reflection or their picture for about five minutes and help them notice any details they may not otherwise notice. For example, "What color is your hair?" or "Are you smiling? How many teeth do you have showing?" The kindergarteners will most likely not incorporate all of the details you point out, but doing so will help raise their awareness.
Tell the children to draw the shape of their head. Draw on the chalkboard or overhead projector the different types of shapes a person's face can have, such as square, rectangle, pointy or round.
Have the children insert the eyes while noting the different shapes eyes come in. This will help the kindergartener be aware of their own facial features and how they translate into general shapes on paper. Show them how to erase their work and redraw it if they want to try again.
Continue this pattern for the rest of the facial features such as the nose, lips, ears and eyebrows. Add general larger guidelines for the hair.
Allow the kindergarteners begin to color the different parts of their self-portrait, matching their eye color and hair color.