Yes I have given myself quite a task with this scene! Ignore the colours. They are there to help me differentiate the various elements in the drawing. Each square is one centimetre (But not on your browser) and this is equivalent to one foot on the canvas.

When I drew in the outlines I deliberately did this freehand so that I had wobbly lines. These contrast with the ruler-drawn grid which helps me see them - and if an upright slopes a bit such as the pillar on the right - well at least I can see it is a pillar and will straighten this up during the transfer.

When drafting out the original sketch I made a point of keeping all the vanishing points within the drawing. See the Horizon line /Eye line which is the dotted line just above the six feet mark. On that line are a series of small circles. Each one of these is the vanishing point for a building. I give each building a name (any old name will do as long as I know which I am referring to) So you will see below each vanishing point is a name to tell me what building this VP is.