I have been a fan of BJ Fogg's Tiny Habits methodology for breaking bad habits and learning good (often new) habits. BJ Fogg did not write this book. James Clear did, with methodologies that are strongly drawn from Fogg's work.
Fogg's new habit forming process is 1. start small (like, way smaller than you just thought for "small"), 2. piggyback on an existing routine, and 3. reward yourself immediately after doing the new habit. Fogg has shown much success at Stanford with this process, and I love it. It works very, very well for me.
Fogg does not have a book about this particular technique of developing good habits. With this book, James Clear does.
Atomic Habits is pretty much a long version of those three steps from BJ Fogg. Until Fogg writes a book on them, this is a fantastic substitute, interpretation of Fogg's work.
Much of the book is rah-rah, how-to-internalize-good-internal-chatter, "obvious," self-help rhetoric, which, let's face it, if you're picking up this book to learn good habits, you actually need. And, while I'm not a fan of the "habit journal" (you can draw lines on a notebook page for the same effect), I do appreciate the habit making guides in the book.
For anyone not a Fogg fan or even aware of BJ Fogg, I strongly recommend this book. If you don't have good habits, aren't the person you want to be, ignore the kabillion quotes I have from the book here, grab a copy and read it.
It is so easy to overestimate the importance of one defining moment and underestimate the value of making small improvements on a daily basis. Too often, we convince ourselves that massive success requires massive action.