Codes of Conduct
I am a big fan of having, following, and enforcing a Code of Conduct (CoC) in all projects where I participate. If by any chance they do not have one, I always seek to collaborate with the project maintainers to adopt one that aligns properly with their values. So far I have seen great results, we all grow together, and ensure a safe and civilized space for everyone.
My favorite Code of Conduct, is Contributor Covenant. It is pretty easy to understand, pretty easy to implement, and it is backed by a lot of open source projects.