Working with slight tweaks in the illustration process - editorial illustration gives you a fair amount of latitude - I tend to work to an Instagram square composition, I further keep the imagery simple but allow enough space for text, slogans or a description if required. As someone who was trained as both a graphic artist and graphic designer - lino cuts, Serigraph*, lithography, the ability to break down images to a series of flat shapes comes naturally.
As a wet photographer, ie analogue process I also worked with lith-film, which is both graphic and teaches to see tons as a series of planes.
I also loved the op-art, dayglo posters of the 60s and 70s which where always a surprise when passing them in the street - their vibrant colours caught my eye and I would often stop to look at them.
* Screen printing is a printing technique where a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil.
