Title tags are yet significant, but it’s not a good thought to over-improve them.
Descriptions yet don’t seem to add much position value, but can assist encourage clicks.
Header tags still need to be relevant.
URL still preferably mentions the keywords.
Content is now about semantically relevant backing keywords, not multiple mentions of the keywords. The example selected is a recipe, because in order to make béarnaise sauce there are particular ingredients that are 100 percent relevant to the eventual result. One way of checking what keywords Google might consider as relevant is to do a ‘~keyword’ (or tilde) search. Other hands, let’s be honest, involve nothing more than common sense and knowing your subject.
Video and other ‘rich’ content can be utile full on a page to raise engagement levels, reduce bounce rates and also to appear alongside results as illustrated.
Internal links need to follow the "reasonable surfer" patent. It makes sense in the "perfectly improved page" example above to link to peppercorn sauce as an alternative to béarnaise.
Facebook/Twitter/other login comments are a way of sharing the content on other platforms. The direct SEO profit may be debatable, but it never hurts to get your content in front of a huge amount of people. With Google Search plus Your Globe, it could be that adding a Google plus login is more significant than anything else.
User reviews add regular content to the page, which can also be coded to contain micro formatting instructions and add other elements to your listings in search engine result pages.
Newsfeeds only share content that already exists to some other place, but they contribute to an overall impression of the page varying on a regular basis.
Its price noting that the “perfectly improved page” above will not be perfect for all verticals, or for all brands – not everybody has the power to add customer reviews to their product pages.
While there's no one-size-fits-all solution, hopefully the above list will give you some counsel on how to perfect your on-page SEO.