React.js best practices and conventions

I’ve been using React.js for a little while now, both in my 9 to 5 job and for my own projects, and during that time I have started evolving my own set of React.js best practices. The following guidelines mostly focus on component structure and JSX. However, they are not hard and fast rules, but more of an opinionated set of guidelines I choose to adhere to that make my code more readable, more robust and easily maintainable.