I went over the two previusly posted studies, but did not achieve any improvement of note. I cut a chunk off the first one because it defied any attempts to integrate it into the rest. I prefer it the way it was before! Too late now! It isn't quite as dark as the photo makes it.
The second study retained its size (A3) but did not make much headway either. Again, I think I used too many dark shades. I eventually decided to to let it go. After all, it's only experimental work. But I've learnt my lesson. I won't go back over any aquadoodles in future.