Find two or more images to help you see details of the city and lightly sketch specific buildings, monuments, and iconic landmarks of a city. Rearrange the items to create an interesting composition.
Create your own design. Make sure to change your picture from the original photos, add items of interest, murals, fountains, trees, flowers, bicycles, people, cars, clouds, etc.
Plan out your color theory.
Paint your watercolors in a loose style and mix colors.