Let each child experiment and doodle with pastels on paper and encourage him to vary the lines he draws -- squiggly, jagged, thick and thin. Ask him to draw an area that is light, which is achieved by using only slight pressure with the oil pastel, and other areas that are darker where the oil pastel has been applied more heavily. Give each student a piece of paper towel to wrap around his finger and ask him to blend shapes and lines together to see what kinds of colors can be produced. A variation of this experiment is to give each student only the primary colored oil pastels -- red, yellow and blue -- and ask him to blend the secondary colors -- orange, green and violet.
Give each child a white-colored oil pastel and ask her to draw only the outline of a shape on white watercolor paper. Have the child paint the page with watery watercolors and observe how the paint resists the areas where the oil pastel has been drawn. Subsequent lessons can be more detailed.