Help with setting up Href Lang

[Ginjarou]

Hi all,

I'm working on a multi-lingual website which doesn't yet have any href lang tags / headers inserted nor has any kind of sitemap - so I'm pretty much free to implement href lang how I choose.

Reading Google's guide and other guides e.g. Yoasts, I understand there are three ways to implement this:

1. HTML Tags
2. HTTP Headers
3. Sitemap

However, these guides all recommend only using only ONE of the three methods but none say how a sitemap should be created if you choose to use option 1 or 2.

So if I was to implement href lang using HTTP Headers - should my sitemap (when I create one) not include any kind of rel="alternate" links?

I'm considering using the HTTP Headers option as we also have pdfs in multiple languages and then creating multiple sitemaps for each language and listing all of these in my robots.txt file e.g.

sitemap: website.com/en/
sitemap: website.com/de/

I'd be really keen to hear thoughts on this approach and any advice as I'm not certain on the best approach - especially as the guides I find all just say the same thing as Google's and are just worded slightly differently.

Thanks.