While Google is on record as stating these quality raters do not directly influence where you rank (without more senior analysts making a call on the quality of your website, I presume?) – there are some things in this document, mostly of a user experience nature (UX) that all search engine optimisers and Webmasters of any kind should note going forward.

When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
At Yoast, we practice what we call ‘holistic SEO‘. This means that your primary goal should be to build and maintain the best possible website. Don’t try to fool Google, but use a sustainable long-term strategy. Ranking will come automatically if your website is of extremely high quality. Google wants to get its users to the right place, as its mission is to index all the world’s online information and make it universally accessible and useful.
When you write a page title, you have a chance right at the beginning of the page to tell Google (and other search engines) if this is a spam site or a quality site – such as – have you repeated the keyword four times or only once? I think title tags, like everything else, should probably be as simple as possible, with the keyword once and perhaps a related term if possible.

SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.[50] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.[51]
QUOTE: “(Google Panda) measures the quality of a site pretty much by looking at the vast majority of the pages at least. But essentially allows us to take quality of the whole site into account when ranking pages from that particular site and adjust the ranking accordingly for the pages. So essentially, if you want a blunt answer, it will not devalue, it will actually demote. Basically, we figured that site is trying to game our systems, and unfortunately, successfully. So we will adjust the rank. We will push the site back just to make sure that it’s not working anymore.”  Gary Illyes – Search Engine Land
An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines[18][19][52] are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the online "spider" algorithms, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility,[53] although the two are not identical.
The world is mobile today. Most people are searching on Google using a mobile device. The desktop version of a site might be difficult to view and use on a mobile device. As a result, having a mobile ready site is critical to your online presence. In fact, starting in late 2016, Google has begun experiments to primarily use the mobile version of a site's content42 for ranking, parsing structured data, and generating snippets.
Many blogging software packages automatically nofollow user comments, but those that don't can most likely be manually edited to do this. This advice also goes for other areas of your site that may involve user-generated content, such as guest books, forums, shout-boards, referrer listings, etc. If you're willing to vouch for links added by third parties (for example, if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. The Webmaster Help Center has more tips on avoiding comment spam40, for example by using CAPTCHAs and turning on comment moderation.
QUOTE: “Google Webmaster Tools notice of detected doorway pages on xxxxxxxx – Dear site owner or webmaster of xxxxxxxx, We’ve detected that some of your site’s pages may be using techniques that are outside Google’s Webmaster Guidelines. Specifically, your site may have what we consider to be doorway pages – groups of “cookie cutter” or low-quality pages. Such pages are often of low value to users and are often optimized for single words or phrases in order to channel users to a single location. We believe that doorway pages typically create a frustrating user experience, and we encourage you to correct or remove any pages that violate our quality guidelines. Once you’ve made these changes, please submit your site for reconsideration in Google’s search results. If you have any questions about how to resolve this issue, please see our Webmaster Help Forum for support.” Google Search Quality Team
Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses hidden text, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking. Another category sometimes used is grey hat SEO. This is in between black hat and white hat approaches, where the methods employed avoid the site being penalized but do not act in producing the best content for users. Grey hat SEO is entirely focused on improving search engine rankings.

Structured data21 is code that you can add to your sites' pages to describe your content to search engines, so they can better understand what's on your pages. Search engines can use this understanding to display your content in useful (and eye-catching!) ways in search results. That, in turn, can help you attract just the right kind of customers for your business.
The above information does not need to feature on every page, more on a clearly accessible page. However – with Google Quality Raters rating web pages on quality based on Expertise, Authority and Trust (see my recent making high-quality websites post) – ANY signal you can send to an algorithm or human reviewer’s eyes that you are a legitimate business is probably a sensible move at this time (if you have nothing to hide, of course).
Creating high quality content takes a significant amount of at least one of the following: time, effort, expertise, and talent/skill. Content should be factually accurate, clearly written, and comprehensive. So, for example, if you describe your page as a recipe, provide a complete recipe that is easy to follow, rather than just a set of ingredients or a basic description of the dish.
Comparing your Google Analytics data side by side with the dates of official algorithm updates is useful in diagnosing a site health issue or traffic drop. In the above example, a new client thought it was a switch to HTTPS and server downtime that caused the drop when it was actually the May 6, 2015, Google Quality Algorithm (originally called Phantom 2 in some circles) that caused the sudden drop in organic traffic – and the problem was probably compounded by unnatural linking practices. (This client did eventually receive a penalty for unnatural links when they ignored our advice to clean up).
A page title that is highly relevant to the page it refers to will maximise usability, search engine ranking performance and user experience ratings as Google measures these. It will probably be displayed in a web browser’s window title bar, bookmarks and in clickable search snippet links used by Google, Bing & other search engines. The title element is the “crown” of a web page with important keyword phrase featuring AT LEAST ONCE within it.
QUOTE: “How do I move from one domain to another domain and try to preserve the rankings as best as possible?…do a 301 permanent redirect to the new location (assuming that you’re you’re moving for all time and eternity so this is the good case for a permanent or 301 redirect if you were planning to undo this later or it’s temporary then you’d use a 302 redirect)…. search engines should be able to follow the trail of all the 301 redirects” Matt Cutts, Google
QUOTE: “We do use it for ranking, but it’s not the most critical part of a page. So it’s not worthwhile filling it with keywords to hope that it works that way. In general, we try to recognise when a title tag is stuffed with keywords because that’s also a bad user experience for users in the search results. If they’re looking to understand what these pages are about and they just see a jumble of keywords, then that doesn’t really help.” John Mueller, Google 2016
Sometimes, Google turns up the dial on demands on ‘quality’, and if your site falls short, a website traffic crunch is assured. Some sites invite problems ignoring Google’s ‘rules’ and some sites inadvertently introduce technical problems to their site after the date of a major algorithm update and are then impacted negatively by later refreshes of the algorithm.
The reality in 2019 is that if Google classifies your duplicate content as THIN content, or MANIPULATIVE BOILER-PLATE or NEAR DUPLICATE ‘SPUN’ content, then you probably DO have a severe problem that violates Google’s website performance recommendations and this ‘violation’ will need ‘cleaned’ up – if – of course – you intend to rank high in Google.
When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
Inclusion in Google's search results is free and easy; you don't even need to submit your site to Google. Google is a fully automated search engine that uses web crawlers to explore the web constantly, looking for sites to add to our index. In fact, the vast majority of sites listed in our results aren't manually submitted for inclusion, but found and added automatically when we crawl the web. Learn how Google discovers, crawls, and serves web pages.3