After watching Arcane S2, I was captivated by the stunning sceneries and decided to try applying my workflow to the Piltover garden scene. I also wanted to figure out how they created it. My approach (and how I think they did it) was to roughly build a 3D scene, make a draft render, and then paint over it in a 2D painting software (I used Procreate), all the moving parts (the tree foliage, the spinner, the character) are still kept in 3D with hand painted shader. This way, I could easily add all the hand-painted details to the final product. As they say—and I agree—to make it look hand-painted, you have to paint. I eventually added my own anime leaves billboard shader, and it matched the visual quite well. I rushed this artwork to completion in about 10 days without using any resources from the series (except screenshots for concept art). It was a fun project.
Final Composition
Breakdown Video
Procreate Painting timelapse