Playing around with random placements.

Each small square along the top row contains a single shape, which is rotated by 90 clockwise in each subsequent square. In the following rows, those rotated shapes are placed in an offset, as in
Superimposed on that layer are a sort of random choice of rotated or mirrored shape, not fully random as I did not allow the same shape as on the first layer. the top right and bottom left squares each include a third shape.
In order to bring out or show up the negative soaces, I have not drawn the outside lines of the squares except where the placed shapes combine with the square’s edge.

 Ink on watercolour paper. 10x10cm