First of all, let me say that I was immediately inspired to paint this portrait when I saw the reference photo. I love the backlit figure against the pumpkin patch background, the abundance of rich colors and, of course, the priceless expression on the little girl's face. I knew it was going to be a good painting right away.
I started with a thumbnail sketch, with a bit of color to help me plan the painting and communicate to the client what I see when I look at their photo:
After the sketch, I stretched my paper and made the drawing using the grid method.
A word about using the grid method with portraits: after you find your reference points and locate the facial features, make sure you double-check your drawing with the usual facial proportions rules. I.e, the vertical center line hits the features in the middle, the horizontal lines of the eyes, bottom of the nose, and mouth are parallel, the distance between the eyes is approximately the width of one eye, the lines from the wings of the nose to the inside corners of the eyes are parallel, etc.
Next step: wet-into-wet background wash and ultramarine blue in the shadow areas. I also put light yellow, red, and orange washes over the skin areas.
Next, I continue working on the hair and face, put a wash over the shadow side of the pumpkin and reclaim the round shape of the pumpkin on the right using a scrubber brush.
Next, more work on the pumpkin and main shapes of the face. i also deepen the skin tones using transparent quinacridone red and quinacridone burnt sienna.
Next step. I might be guilty in spending too much time an effort on the hair, but I just can't help it. I like painting hair. I darken the shadows throughout the painting, define the eyes, soften the hard edges around the hand and add detail to fingers and the girl's dress. Almost done.
From the last stage to the completed painting, it's just a matter of deepening the shadows even more and refining the important details. I also add a few spots of semi-opaque yellow to the pumpkin and, in a more transparent manner, the girl's face. These last steps seem fairly insignificant, and you may say that the main idea of the painting was already stated in the previous stage - but they often take the longest time with a lot of reflection and evaluation. When my additions and refinements are no longer making the painting better, I declare it finished.
I find it important to take it slowly at the end, so that I have a lot of opportunities to step away from the painting and come back to it with a fresh eye. It helps me catch myself before I overwork it - although, of course, the level of finish is very subjective. Some other artist would have stopped twenty hours ago, while another one might want to work it to a more realistic stage.