The method I'm using this week... start with charcoal color chalk paint, available at home centers but not art stores. It is matte, highly pigmented and cheaper than gesso. I applied this to a 16x20 black canvas, then gridded off lines on this with pastel and on the reference photo with a sharpie.
Whoa! the color balance sure didn't hold up for this photo, the land part of this is still the charcoal color from the first one, it didn't actually get darker. Must be the time of day. Anyway, I applied white chalk paint to everywhere I want sky in the finished painting, it is more difficult to make the smooth sky tones over dark.
Here I made some form with white acrylic. Then I started to add color in acrylic and forgot to take a picture, so imagination.
The final coat of paint is a glaze with oil paints and liquin. For the sky I did a Bob Ross magic white, added liquin to my white paint and covered the sky then worked in the color, Prussian and Ultramarine blue, the chemtrail and sun added after. The same colors plus raw umber for the sea and sand. Lots of white for the sun on the waves.