[ilikepi]

Check out the "Developer Tools" category on hacks.mozilla.org[1]. When new features are added to DevTools, it's pretty common for blog posts to appear there, often with videos or animations. These are sometimes linked from the official developer release notes of the browser. It's probably not quite what you're asking for, but it's a start...

[1]: https://hacks.mozilla.org/category/developer-tools/

[blitmap]

Thank you very kindly for that. Mozilla would be the best source for stuff like this. :) I had looked on Youtube or on egghead.io and such, but I didn't really find what I wanted.

This is an offshoot, separate topic: I wish there were a Firefox extension for using the compatibility/emulator mode in Devtools to avoid fingerprinting. I want the website to always think I am 1920x1080 (a common res) and have it be easy to pan around in if the viewport does not match the dimensions of Firefox's window/tab.