I start this just doing random doodling at upper black part and because it looks quite nice i start to search reference from my phone. Found one shot month ago at beach with dramatic clouds
BIC ballpoint stick pen drawing on Richeson bulk drawing paper. This started as a contour drawing and just got squiggly (not the original intent). This was clipped to my board for weeks and I would add a few squiggles from time to time when I wanted to make marks, but didn't have inspiration. It's just a bit under 15 inches (12x18 inch paper) and is probably about 25 hours of making little lines and squiggles. The reference was a Dreamstime royalty-free photo.