Paintings change when you start working on them. In this one, based on a tonal collage based on a recent sketch, I was surprised to see the figure of William Shakespeare emerging:
I started off by blocking in mid, light and dark tones, roughly in a 8:5:3 proportion (the concept was to use this overall balance based on part of the Fibonacci sequence) and began to work it up. At this point, I was using yellow ochre (mixed with a little purple), buff titanium (mixed sometimes with a little ochre and sometimes with a little white) and purple (mixed with a little ochre). After a while, the character of the figure began to emerge and I stepped back to evaluate.
I could almost see some turquoise in my minds eye, so I took a photo on my iPad and worked on a few layers with Procreate. Turquoise looked great and I spotted some places for a bit more white and a dark purple wash, which I added in the afternoon. This was all done with a large brush and some paint added with a rubber tipped instrument.