Working from photo references, I began with this small sketch.
I developed a quick drawing to examine composition and get to know the subjects.
Then I did a notan to get my placement and value pattern.
I have refined my palette. I now use glass underneath which I have placed heavy paper painted neutral gray with Value 6-ish on the left half and value 4-ish on the right. In this photo, I am mixing for my acrylic underpainting, beginning with dioxazine purple + white at value 6-ish, and the mix at value 4ish on the right. Later when I do the background trees, I will add a bit of ultramarine blue to the darker mixture to better distinquish negative from positive.
First I did a drawing placing the cows. Then I blocked in their darks.
Next I add a bit of ultramarine blue to the darker purple and block in the background.
I move to oil and begin the painting. First I lay in the colors for the background trees, then the pasture's grass. I'm careful to keep shadows and distant grasses cool.
Next I lay in the darkest darks of the cows.
Now to the orange of the cows on the light side.
Then to the shadows and lights on the whites of the cows. Next, with a sable brush, I blended all the edges carefully.
Now, I define all the details that I want to include.