I don't generally use a ruler. But if there are really long
lines in the painting, or a lot of perspective that needs to
be really right, it saves me a lot of trouble if I find something
needs changing after I get into applying paint!
The thing is, doing this before I start painting gives me the
control I need to get it down right. Then I follow those drawn
lines with careful application of paint (but no ruler), and it
doesn't look mechanical because of the aliveness of my hand
and body movement, however slight. Doing it this way gives
life to those lines.
This is the beginning of a cafe scene at night. I love the bike
which has its own perspective challenges!
In order for this painting to have the composition I wanted
I added pieces of paper to the edges of the photo.
If you go to my teaching blog, you can find out more.
The link is on the right side of this page....Teacher Tips.