This quick study (2 hours) is based on a 19th century botanical illustration, a favorite theme of mine to reference.
The first step to painting a copy is to map out the composition using a mathematical division of the space, and placing the image along the sweet spots of diagonals, horizontals, verticals, using charcoal.I will remove the lines with mineral spirits before continuing with the painting.
I then begin to mix the oil paints, using a limited palette of cadmium red deep and a green that I mixed from ultramarine blue and cadmium yellow light.
Next step, blocking in the background using a combination of the lightest value of the neutral: the middle string of mixed values (the result of mixing the red with green).
Then, a blocking in of the lightest lights over the entire image.
Continue with the darkest darks.
Finally adding middle values to complete the study.