I started using React Native in September 2018. I always forget some things when I build new apps, so I'll keep track of the gotchas on this post.
Some topics, such as navigation, will be fundamental to how I think about apps. Others, will be one-line helpers that make apps work more smoothly.
It's gotten to the point where I find my own answers from 6 months before on certain Github issues.
I'll keep adding over time as I think of more. If anyone thinks these topics would be useful, let me know and I'll elaborate.
I have made libraries to address a number of the topics here, from navigation to design.