I'm trying to do some loose paintings at thumbnail size. I find that if it doesn't look good tiny it doesn't look good big. The values and space really show up when you look at it small because you don't get caught in the details.I sketch the compostion... Paint it in black and white to get the values then do an overlay to get basic color and then noodle by painting over on another layer.
composition then value then color!
Concept artist and creature designer.