As he notes, none of the recommendations are completely new. In all, there are eight recommendations. I’ll give you the short version here:
1. Use rel=canonical when serving content from multiple URLs.
2. Avoid the AJAX-Crawling scheme on new sites.
3. Avoid using “#” in URLs (outside of “#!”).
4. Use Search Console’s Fetch and Render tool to test how Googlebot sees your pages.
5. Ensure that all required resources aren’t blocked by robots.txt.
You should definitely read Mueller’s post for additional details on each of these, including some AMP-specific guidance. Google began sending search traffic to AMP pages last month.
Image via Google