New York City paintings or Warm and cool - 3D cities

This idea I found on someone's blog but have forgotten which one,  it was called warm and cool 3D cities and is a brilliant art lesson for 5-12 year olds.

1. We drew buildings using a straight line with arrows.
2. Then brought lines down to the bottom of the page.
3. Added circles  in sky. We looked at Van Gogh's "starry night' for inspiration.
4. Discussed using light and dark for each side of each building to increase 3D effect!