
Back in 2023, I have looked at how to add relevant hreflang tags to my personal website, which considered adding self-reference to the current language, reference to a translated page (if available), and falling back with x-default to a page that is designed as a language switcher page.
Since then, I thought that this approach was correct, but found out that this solution, on my website, where not all content is 100% translated, is not good for sites fully translated by default.
Here is how I learned from it and how I optimised hreflang and x-default on websites built with Hugo.