The first photo is of the canvas on which I am doing the
preliminary drawing. In the lower corner you can see the
image I am working from.
I use a ruler when I need to really get long perspective lines
right, or else I can be in a situation after applying paint where
I have to make a lot more adjustments. Moving paint around
is messy! So get it right at the very beginning.
HOWEVER, I do not use a ruler once I am painting. I follow
the drawn lines carefully with my brush, but because I am
not using a ruler, there is life to those lines. They don't look
mechanical.
In the second photograph, you can see the image I am using.
I took the photo and had it blown up into a color copy that was
large enough for me to see what I needed to see! Then I
decided the composition needed some changes and so I added
pieces of paper around two edges to add to the image. You can
see the scribbled part that looks like a border.
After doing the above, I made a grid on the painting that is
proportionate to the canvas and started drawing!