I drew in the horizon line first, and then worked on the shapes of the dominant building. I then drew in the balloon shapes and the impression of the landscape below with tops of buildings rising out of the mist.
I decided to paint in the major buildings first, although this is not really the most practical way to work when you are painting silhouettes. I mixed my own purple colour using perylene violet and perylene blue, but I mixed this in varying proportions of the colour as I worked. I painted in the dominant building and its smaller structures first.
I painted the landscape and the dark area on the left hand side of the composition.
I then painted in the sky using a gamboge yellow overpainted with a ready mixed tube orange. I wet the paper first, applied my yellow wash and then a stronger wash of the orange. As this was drying I stronger tones of the orange until I achieved the bright orange required on the horizon line.
When the sky area was 100% dry I painted the white clouds using a titanium white acrylic. I painted in the balloons using my purple mix.
I let the painting dry overnight. I then applied a glaze of the titanium white over the parts of the city that were under mist. When applying a glaze for the purpose of mist, work quickly, use a large brush and ensure the glaze is a strong enough mix of paint to cover the colour underneath the glaze.