I did this digital painting with two painting programs, My Paint and Krita. I like digital painting because you can save the drawing/painting at any stage and improve on it.
I am finding that as my skills improve, I can go back over my saved drawings and apply them again.
I did not use layers, I saved the painting at different points and worked on it from there. I have a heavy hand and tend to use thick dark strokes, at the same time I love a soft pastel look. It is fun to play and experiment with both.