After observing some house shapes, printing straight lines with white paint and the edge of a piece of card, enhanced by some simple brush lines, simplified the forms and moved these images pleasingly towards abstract.
In more realistic vein, drawing with white on black sometimes brought variety and freshness to the activity as well as to the children’s completed images.
There are also times when adding some black pastel to black paper can be very effective, particularly when the paper is not quite as black as the added pigment.
(For anyone interested, notes on the teaching approaches that helped children towards these outcomes are on the COMMENTARY PAGES of this blog.)