Vincent Van Gogh
The first pictorial decision painters make is to select the material, shape, size, and color of the surface. If it is a rectangle, the second pictorial decision is about format. Do I position it on the short or long side and why? The third pictorial decision is about where the first mark and subsequent marks go and how their interaction activates and divides the rectangle. The overarching issue is how these decisions detract or contribute to the expression of the painting.
Van Gogh used the double square extensively. Why did he use this shape, and what compositional challenges did face by using this particular shape and format?
Link Double Squares, Wiki