I use Dr. Edwards' book for drawing exercises, in my 6th grade, before we
tackle perspective drawing. I start by telling them that we are going to
"exercise" a bit before we actually draw. I also have them draw a landscape picture
to the best of their ability so that we will have a "before" picture and can
gauge what they have learned in the end.
The lessons I use from the book include vase-faces and monster vase-faces,
upside down drawing, blind contour of the hand and drawing negative space. I
lead them with the idea that we would all draw better if we drew what we actually
saw (right brain) rather than what our left brain tells us it knows! Then I
move into the attributes that make a drawing look more realistic from a
perspective point of view. Things such as position on the picture plane,
overlapping, size, and detail/value. The resulting pictures are always much better. I
let them know that they can learn "tricks" to make their drawing better. I
hope this helps a little.