After deciding the composition for a new painting, I make a few sketches in pencil. By then I am usually itching to really get started. I draw the whole painting with a waterproof black pen. Now my "coloring book" is ready to go!
Here I've decided the basic color for each shape. I can still change my mind and make the yellow doors orange or green, but it's much easier to proceed when everything has some color.
I go over the color many times until it feels right. I was concerned about how to make the water reflective, so I made many small marks with my brush! After I've finished painting, I go over all my black lines one more time and the image pops out & it's finished!