Hello Denise in Broom again.
We used to run those sort of courses here once upon a time.
Our teacher Aid classes have some of those sort of non art
expectation participants in them too.
When you teach them some basic perspective skills they are amazed at
the results. ie. looking down a long corridor then putting in
Pavement art may work with them too. Reproducing an illustration
from a favourite contemporary children's book in chalk works well.
Large vertical Chalkbaords are better if they are available. Then Photograph the
results. They can work on something that big for a whole day.
Basic pattern and non figurative experiments which can be used later
as wrapping paper also frees them from the worry of drawing
Collograph printing too removes the "I can't draw" fear.