Got back from a painting course at Art Holidays in Dorset, on Monday. This was painted as one of my evening demonstration paintings... next door's black and white moggy.
After sketching the outline with a 5B pencil onto 200lb Bockingford paper, I soaked the paper and then mixed colours on the page to create a soft, atmospheric foundation wash, lifting out some areas with a damp brush. Once it was dry, I began to build up the washes on dry paper. All in all, the painting took about an hour, from start to finish.