I found this lesson in http://artprojectforkids.blogspot.com
I thought that it is a great activity to teach my 4th graders smudging oil pastel and blending colors.
1) Position the paper horizontally, and draw three lines that tilt to each other. The three lines represent the foreground, middle ground and background.
2) Draw any simple shape on each line.
3) Color your drawing with oil pastel. Use a light and dark shade of a particular color (e.g. green and yellow green, blue and sky blue, chocolate brown, light brown and orange) to give an illusion of depth to your work.
This is the sample I showed my students. I made a little deviation from the original procedure of Kathy Barbro.
This art work was made by Jerry of Grade 4-C
Art Work by Elizabeth Park of Grade 4-B
Art Work by Jean Kim of Grade 4-B