First I applied the cardboard with 3 layers of gesso.
I transfered my sketch on the cardboard and used acrylic paint (burnt umber) to trace the lines.
After that I used the same acrylic paint to block in the shapes to get a good sence of the light/dark values and contrasts. I tried to make it not to dark except for the eyes were the main focus will be.
Then I started with my oil pallet. First layer with oils are mainly the greenish and bluish colors applied with thinned paint. These are the main cool colors, after that I started building up layers with a more warm pallet for the background (raw Sienna and Camium yellow mixed with Zink white).
For the figure I continued using cooler bluish colors to get a nice contrast with the background.
The whole piece is build up in many glacing layers of oil paint. Spend about 6 hours total on it.