Bit of a tangent but does anyone have good learning materials on doing things with Emacs Lisp beyond just staring at the source of packages?

I have the Mastering Emacs book and read through most of it, which gives me a good idea for some stuff... but I really would like to have good ideas for the right kind of design patterns for common things.

Have you read through the Emacs Lisp Intro and Elisp manuals in Info? The latter is especially helpful as a reference.

All of Prot's packages[1] are really nicely designed imho.

[1]: https://protesilaos.com/emacs/

I started getting a little more into ELisp after reading The Land of Lisp, though its probably a bit basic. If I were to try to get better at ELisp through reading books/docs, I'd look into Common Lisp material.