For young kids -candy wrappers, coke and sprite cans worked really well for
my students when I taught at the middle school.
Now in art 1- I have been known to start with giving them each a handful of
popcorn on a paper towel and ask them to draw the pile before they eat it! I
have also done a similar activity with cookies. These are a bit better (more
"interactive") than my exercises with "crumpled up paper"! But, the drawing
subject is left up to me and how I feel at the time.
Kathy in Kalamazoo