As I love the children's book illustrations by Hans de Beer, who uses these serene backgrounds, figuring out how to do watercolor washes totally was  on my bucket list. But it's hard.... and as I just used two kinds of cheap watercolor paper, there is definitely room for improvement there ;-) But what a fun and relaxing thing to do, turning the page around and around. I've incorporated that technique with my large canvas paintings by now, so thanks for opening my mind for yet another playful way to move the paint around!

One QUESTION that came up for me was: For single color flat washes, what is the advantage of turning the paper around compared to tilting the paper and just pulling the paint down stroke by stroke?

1st+2nd attempt:
These turned out a bit patchy and I had some back flow and blooming effects with the indigo. Probably there where some water drops on the tape that pushed the color back from the edges during the drying process. Learning: Wipe those off before you let everything dry ;-)

3rd+4th attempt: For the third one I tried a monochromatic cloudy look, but my water levels probably where a bit top low, so you can see where I added paint with the brush... On the right one I actually didn't use the technique you showed but the "classical" tilting of the page and pulling the paint down. For the even one color look I was actually more successful with this method.

5th+6th attempt: Here I tried the cloudy two pigment look. In the left one I had some issues with patches of paper that where drying faster than other therefore preventing the paint to spread evenly. Adding some more water during the process definitely didn't help and left me with some additional hard edges in the top left corner. But the second one which was emerald green and yellow worked out very well.

7th+8th: Here I tried to get darker edges on purpose for that old weathered paper look. Turned out pretty neat, although there are some weird stripes and patches in the right one. I suspect it's a paper problem. I used very cheap watercolor paper....

9th+10th attempt: On the left side I again tilted the paper and just pulled the paint down. I got some darker spots on the edges because the paper buckled a bit and therefore the paint pooled again. On the right side I used the turning method again. Some weird granulation going on there....