This involved a large sheet of paper (about A1 or A 2) placed on the floor, a 3 inch decorator's brush taped to a long stick, lots of cheap black paint and some crayons or oil pastels.
The results were very abstract and great fun though I will admit to having enhanced the graphic qualities a little in Photoshop.
Gosh where is all this leading? I wish I knew.....
* As an aside, courses like this are sadly no longer available at this lovely UK venue.