Here is a process overview article on the Delicious Brains blog about creating custom block using React and using ACF. It does not go into depth but links to resources for various steps.

Cedric, the author of BricksProps, does a deep dive into BEM and how to use it.

Adam Lowe has shared his premium course on YouTube for free. It goes in-depth on how to create a classic theme using Pinegrow. It is a great resource on creating a classic theme and on Pinegrow.

Here is a Beaver Builder tutorial on how to use the new Box Module. The Box Module give the ability to use Flexbox and CSS Grid.

A course on the UX of search by Vitaly Friedman. Recommended.

Creating and managing block patterns is pretty straightforward. Here is a tutorial on the process.

Here is a tutorial showing how to install WP-CLI and perform a number of common WordPress tasks using it.

Here is a fun video from Kevin Power playing with CSS currentColor and color-mix. It might be useful for people trying to create light and dark mode color palettes.

In this video Paul Charlton shares his enthusiasm for GutenBricks, a plugin that lets you create Gutenberg blocks from Bricks Builder templates. It is a way to provide Gutenberg blocks for clients so they can edit the content, without changing the layout and styles.