Dan Abramov shared a short post on some key principles the React team sticks to. Some solid general advice here, it's not explicitly related to React.
Absorb the Complexity
Making React internals simple is not a goal. We are willing to make React internals complex if that complexity lets product developers keep their code easier to understand and modify.
Hacks, Then Idioms
We need to allow hacks using escape hatches, and observe which hacks people put in practice. Our job is to eventually provide an idiomatic solution for hacks that exist in the name of better user experience. Sometimes, a solution might take years. We prefer a flexible hack to entrenching a poor idiom.
These two stood out because they're the opposite of how I generally need to think when building applications (although they make perfect sense in the context of something like a lower level framework). Either way, lots of food for thought in here.
Read all principles on overreacted.io.