Select 3 body parts on a person who will serve as your model, draw a composition of those 3 body parts 3 times (on 3 separate pages) using pencil, but each time draw one body part with exaggerated scale (proportions should still be correct – only scale is altered).  Make sure that you fill the entire page with each drawing (avoid small in the middle of the page). Show evidence of time invested – it is very easy to tell when a student has spent 10 minutes on a drawing versus 30 minutes.

NOTE:  Make the scale VERY exaggerated so a viewer could tell at a glance which object has been altered.  Exaggerate the scale even more than in the example below:

this one has better scale exaggeration: