Does anyone have any resources for learning how to do very beautiful clean technical drawings like this? I have some art skill but not the kind that translates to such clean technical drawings with this nice personality. Would love to be able to make some for my own projects.

From the home page:

Question: How do you make the illustrations?

Answer:

I get asked this more than anything else but honestly, I don't have a good answer.

I make them by hand, in Figma. There's no secret - it's as complicated as it looks.

The Advanced Edition of the book will include a tutorial explaining how I make them, where I get references and inspiration from.

This has some great examples, enough to get started and provide some inspiration, but is sadly incomplete.

https://rougier.github.io/python-opengl/book.html