I always think this is the "work" side of painting a mural. It is a necessary part of the process and important to get right, because no matter how well you paint it, if the drawing is incorrect it will show. In this photo I have measured and drawn the mural onto the wall, and marked in the horizon line.
The little bit of blue masking tape that you can see in the middle of the picture is holding a piece of string at the vanishing point. This is so that when I come to draw in the houses, I can align the string with the building and find the correct perspective.
I have sketched in the details of the mural and outlined the drawing in a dilute mixture of paint.
At this colourful stage I have covered the window frame with masking tape, because once the sky has had several layers of paint, the window would be completely covered, and by protecting it now saves me from having to re-draw it again later. I have also masked the horizon line and the edges of the houses for the same reason, and then I have just loosely scumbled a warm underwash over the whole mural. This will give an added warmth to subsequent layers and help to unify the painting.
Now the fun begins !!!!!