Professionally, I work as backend developer on a project that uses React in the frontend. I do have experience working with our React code of course, but it's far from the main thing I do.
Since I'll be using React in a bigger personal project I'm working on I wanted to learn the fundamentals in a formal way. I took an intro React course on egghead.io. Though the course was fine, I have to say, I just think using a book or written tutorial just works better for me. The Road to React is one of a few well regarded books on React, and so I worked through all the chapters. The advice at the end of the book is good: just go write a react project. Don't do any more tutorials.
So here is my first react "projectlet" - an implementation Tic Tac Toe. Nothing fancy here, just a working version of tic-tac-toe. It might be fun to add in an AI opponent, but that really has little to do with React. And of course, there's plenty of room to improve the look.
FYI: I'm really falling behind on my TIL posts! Today I'm talking about something a few weeks old.