I've never been able to work just one area and then move on to another. I have to get the canvas covered and then go back and forth all over it. Not good for
alla-
prima at all - it's easy to make mud doing that.
Whenever I've tried to finish one part of a painting at a time, it quickly begins to look like different people have been taking turns at it!
I think the only reason the squash painting worked out was because it was so small, no room to fuss with anything.
I've seen one other artist's demo (can't remember who) where she began like the video above - no drawing beforehand, just started with the eyes and worked out from there. It's amazing to me that anyone can do that. I had to give it a try (once, several years ago), ended up with a rather disjointed Picasso-like face!