Walter Pall just posted a nice series of photos on the progression of a Prunus #40 Bonsai into a very nice Clump style. Walter has high quality photos and you can learn a lot by studying his progression photos on any number of different tree species. I have posted this article on the Clump page, under Styling(Design) and listed under Bonsai Basics. Photo below courtesy of Walter Pall.

https://rockymtnbonsai.com/index.php/bonsai-basics/styling-design/clump/