Begin small, then work up

I always start my paintings in a small file, something like 1,000 pixels at 72DPI. At this low level of resolution, I can’t start working on the details, which helps me stay focused on the general shape, volume and light. I increase the resolution progressively (150, 200 and finally 300DPI) when I feel that, for example, the colour base is perfect and won’t be changed.