Ask for a technical and search audit for your site to learn what they think needs to be done, why, and what the expected outcome should be. You'll probably have to pay for this. You will probably have to give them read-only access to your site on Search Console. (At this stage, don't grant them write access.) Your prospective SEO should be able to give you realistic estimates of improvement, and an estimate of the work involved. If they guarantee you that their changes will give you first place in search results, find someone else.
Google is falling into a familiar pattern. First, they offer web publishers increased visibility and SERP display options. Next, they incent participation in specific formats and data structures. Finally, they take that data for themselves, changing the SERPs to favor advertising, their own properties, and/or instant answers that can reduce publisher traffic. For web marketers, it's a prisoner's dilemma. In this presentation, Rand will show data on how Google is being used today, how it's changing, then dive into strategic initiatives and specific examples of how savvy players can build a moat to protect against long-term risk.

All you need to notice from this kind of articles is what I & most of the others newbies focusing on the SEO link-building. I have seen many bloggers spending time on different ways of SEO link building instead of providing the value to the content and its social promotions. You may call it ignoring the Google, but we all know that the Google bot doesn’t ignore anchored dofollow or nofollow backlinks to calculate your PageRank.

To prevent users from linking to one version of a URL and others linking to a different version (this could split the reputation of that content between the URLs), focus on using and referring to one URL in the structure and internal linking of your pages. If you do find that people are accessing the same content through multiple URLs, setting up a 301 redirect32 from non-preferred URLs to the dominant URL is a good solution for this. You may also use canonical URL or use the rel="canonical"33 link element if you cannot redirect.

QUOTE: “Some pages load with content created by the webmaster, but have an error message or are missing MC. Pages may lack MC for various reasons. Sometimes, the page is “broken” and the content does not load properly or at all. Sometimes, the content is no longer available and the page displays an error message with this information. Many websites have a few “broken” or non-functioning pages. This is normal, and those individual non-functioning or broken pages on an otherwise maintained site should be rated Low quality. This is true even if other pages on the website are overall High or Highest quality.” Google

So you have a new site. You fill your home page meta tags with the 20 keywords you want to rank for – hey, that’s what optimisation is all about, isn’t it? You’ve just told Google by the third line of text what to filter you for. The meta name=”Keywords” was actually originally for words that weren’t actually on the page that would help classify the document.

The SERP is the front-end to Google's multi-billion dollar consumer research machine. They know what searchers want. In this data-heavy talk, Rob will teach you how to uncover what Google already knows about what web searchers are looking for. Using this knowledge, you can deliver the right content to the right searchers at the right time, every time.

QUOTE: “I don’t think we even see what people are doing on your website if they’re filling out forms or not if they’re converting to actually buying something so if we can’t really see that then that’s not something that we’d be able to take into account anyway. So from my point of view that’s not something I’d really treat as a ranking factor. Of course if people are going to your website and they’re filling out forms or signing up for your service or for a newsletter then generally that’s a sign that you’re doing the right things.”. John Mueller, Google 2015

QUOTE: “In place of a pop-up try a full-screen inline ad. It offers the same amount of screen real estate as pop-ups without covering up any content. Fixing the problem depends on the issue you have for example if it’s a pop-up you’ll need to remove all the pop-up ads from your site but if the issue is high ad density on a page you’ll need to reduce the number of ads” Google, 2017
All you need to notice from this kind of articles is what I & most of the others newbies focusing on the SEO link-building. I have seen many bloggers spending time on different ways of SEO link building instead of providing the value to the content and its social promotions. You may call it ignoring the Google, but we all know that the Google bot doesn’t ignore anchored dofollow or nofollow backlinks to calculate your PageRank.
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.

“Doorways are sites or pages created to rank highly for specific search queries. They are bad for users because they can lead to multiple similar pages in user search results, where each result ends up taking the user to essentially the same destination. They can also lead users to intermediate pages that are not as useful as the final destination.

Great SEO is increasingly dependent on having a website with a great user experience. To make your user experience great requires carefully tracking what people do so that you always know where to improve. But what do you track? In this 15-minute talk, I’ll cover three effective and advanced ways to use event tracking in Google Analytics to understand a website's user.
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.
We’ve used other tools in the past, but SE Ranking offers more up-to-date data and information, which benefits our agency and clients. SE Ranking allows us to access historical data with just a few clicks without ever having to leave the interface. From daily ranking updates to current search volume trends, there are numerous aspects that are essential when formulating client strategies, and with SE Ranking’s continuously updated system we are able to use this data to help our clients succeed.
A lot of optimisation techniques that are in the short term effective at boosting a site’s position in Google are against Google’s guidelines. For example, many links that may have once promoted you to the top of Google, may, in fact, today be hurting your site and its ability to rank high in Google. Keyword stuffing might be holding your page back. You must be smart, and cautious, when it comes to building links to your site in a manner that Google *hopefully* won’t have too much trouble with, in the FUTURE. Because they will punish you in the future.

Page and Brin founded Google in 1998.[23] Google attracted a loyal following among the growing number of Internet users, who liked its simple design.[24] Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.[25]

I’ve got by, by thinking external links to other sites should probably be on single pages deeper in your site architecture, with the pages receiving all your Google Juice once it’s been “soaked up” by the higher pages in your site structure (the home page, your category pages). This tactic is old school but I still follow it. I don’t need to think you need to worry about that, too much, in 2019.

Many websites rely on other traffic generation methods such as traffic from social media, email, referrals, and direct traffic sources over search engines. For sites like these, SEO errors aren’t as important because search engines aren’t their #1 traffic source. For a smaller website, a couple of errors can have a much bigger negative effect than those same errors on a larger website.

QUOTE: “So there’s three things that you really want to do well if you want to be the world’s best search engine you want to crawl the web comprehensively and deeply you want to index those pages and then you want to rank or serve those pages and return the most relevant ones first….. we basically take PageRank as the primary determinant and the more PageRank you have that is the more people who link to you and the more reputable those people are the more likely it is we’re going to discover your page…. we use page rank as well as over 200 other factors in our rankings to try to say okay maybe this document is really authoritative it has a lot of reputation because it has a lot of PageRank … and that’s kind of the secret sauce trying to figure out a way to combine those 200 different ranking signals in order to find the most relevant document.” Matt Cutts, Google

Some page titles do better with a call to action – a call to action which reflects exactly a searcher’s intent (e.g. to learn something, or buy something, or hire something. THINK CAREFULLY before auto-generating keyword phrase footprints across a site using boiler-plating and article spinning techniques. Remember this is your hook in search engines, if Google chooses to use your page title in its search snippet, and there is a lot of competing pages out there in 2019.
The audit is for all pages and not only one. What happens in the majority of the cases is that pages / posts have similarities so you can group them together. For example the pages of a website may be ok but the blog post pages may be missing titles. It’s a lot of work especially for a 500 pages website but you can start from the most important pages first and work your way to the rest