Add a "Best Practices" document
I'd like to have a document that describes how we think people should write pandas code.

This introduces a bit of friction when documenting something, since you'll need to decide "does it go in best practices or the user guide?" But I think the idea of a "best practices" document with opinionated, short examples and prose, linking back to the user guide and API docs, is valuable.

I've started a notebook at https://mybinder.org/v2/gh/TomAugspurger/pandas-best-practices/master?filepath=Best%20Practices.ipynb

Are there any sections you would add / remove?

Would you structure it differently?

(tangentially, I'd like to explore how we can incorporate binder into our documentation).