Think about the words that a user might search for to find a piece of your content. Users who know a lot about the topic might use different keywords in their search queries than someone who is new to the topic. For example, a long-time football fan might search for [fifa], an acronym for the Fédération Internationale de Football Association, while a new fan might use a more general query like [football playoffs]. Anticipating these differences in search behavior and accounting for them while writing your content (using a good mix of keyword phrases) could produce positive results. Google Ads provides a handy Keyword Planner34 that helps you discover new keyword variations and see the approximate search volume for each keyword. Also, Google Search Console provides you with the top search queries your site appears for and the ones that led the most users to your site in the Performance Report35.
Use common sense – Google is a search engine – it is looking for pages to give searchers results, 90% of its users are looking for information. Google itself WANTS the organic results full of information. Almost all websites will link to relevant information content so content-rich websites get a lot of links – especially quality links. Google ranks websites with a lot of links (especially quality links) at the top of its search engines so the obvious thing you need to do is ADD A LOT of INFORMATIVE CONTENT TO YOUR WEBSITE.

After the audit has been completed, your team will be invited to a presentation in which your SEO specialist will talk through the findings and recommendations. The Three Deep SEO team will walk you and your team though the roadmap to completion so you know what to expect and when. In addition, you will receive a comprehensive analysis of your site’s health. All of these are customized to you and your specific situation.

Google expects pages to “be edited, reviewed, and updated on a regular basis” especially if they are for important issues like medical information, and states not all pages are held to such standards, but one can expect that Google wants information updated in a reasonable timescale. How reasonable this is, is dependant on the TOPIC and the PURPOSE of the web page RELATIVE to competing pages on the web.
Everything for Google these days comes down to “Customer Experience”. Page speeds, table of content, the relevancy of content, length of content, uniqueness of content, jump links, video in the content, relevant headers, less broken links, customized 404 pages etc are all indicative of improving customer experience on th website and hence helps you rank better.

QUOTE: “Starting April 21 (2015), we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high-quality search results that are optimized for their devices”. GOOGLE
QUOTE: “high quality content is something I’d focus on. I see lots and lots of SEO blogs talking about user experience, which I think is a great thing to focus on as well. Because that essentially kind of focuses on what we are trying to look at as well. We want to rank content that is useful for (Google users) and if your content is really useful for them, then we want to rank it.” John Mueller, Google 2016

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

In 2007, Google announced a campaign against paid links that transfer PageRank.[30] On June 15, 2009, Google disclosed that they had taken measures to mitigate the effects of PageRank sculpting by use of the nofollow attribute on links. Matt Cutts, a well-known software engineer at Google, announced that Google Bot would no longer treat any nofollow links, in the same way, to prevent SEO service providers from using nofollow for PageRank sculpting.[31] As a result of this change the usage of nofollow led to evaporation of PageRank. In order to avoid the above, SEO engineers developed alternative techniques that replace nofollowed tags with obfuscated JavaScript and thus permit PageRank sculpting. Additionally several solutions have been suggested that include the usage of iframes, Flash and JavaScript.[32]
You don’t want to “keyword stuff” and cram your core keyword and every possible variation of it into your alt attribute. In fact, if it doesn’t fit naturally into the description, don’t include your target keyword here at all. Just be sure not to skip the alt attribute, and try to give a thorough, accurate description of the image (imagine you’re describing it to someone who can’t see it – that’s what it’s there for!).
Having a different description meta tag for each page helps both users and Google, especially in searches where users may bring up multiple pages on your domain (for example, searches using the site: operator). If your site has thousands or even millions of pages, hand-crafting description meta tags probably isn't feasible. In this case, you could automatically generate description meta tags based on each page's content.
Don’t break Google’s trust – if your friend betrays you, depending on what they’ve done, they’ve lost trust. Sometimes that trust has been lost altogether. If you do something Google doesn’t like such as manipulate it in a way it doesn’t want, you will lose trust, and in some cases, lose all trust (in some areas). For instance, your pages might be able to rank, but your links might not be trusted enough to vouch for another site. DON’T FALL OUT WITH GOOGLE OVER SOMETHING STUPID
What does it mean for a site to be SEO friendly? It goes beyond just posting quality content (though that’s a very important part!). There are all kinds of ways big and small that can prevent your site from being seen by search engines and thus by users. Our free audit tool begins by looking at some of the most important facets of your website you might not even be aware of.
SEO platforms are leaning into this shift by emphasizing mobile-specific analytics. What desktop and mobile show you for the same search results is now different. Mobile results will often pull key information into mobile-optimized "rich cards," while on desktop you'll see snippets. SEMrush splits its desktop and mobile indexes, actually providing thumbnails of each page of search results depending on the device, and other vendors including Moz are beginning to do the same.

Google expects pages to “be edited, reviewed, and updated on a regular basis” especially if they are for important issues like medical information, and states not all pages are held to such standards, but one can expect that Google wants information updated in a reasonable timescale. How reasonable this is, is dependant on the TOPIC and the PURPOSE of the web page RELATIVE to competing pages on the web.
QUOTE: “Cleaning up these kinds of link issue can take considerable time to be reflected by our algorithms (we don’t have a specific time in mind, but the mentioned 6-12 months is probably on the safe side). In general, you won’t see a jump up in rankings afterwards because our algorithms attempt to ignore the links already, but it makes it easier for us to trust the site later on.” John Mueller, Google, 2018
I think ranking in organic listings is a lot about trusted links making trusted pages rank, making trusted links making trusted pages rank ad nauseam for various keywords. Some pages can pass trust to another site; some pages cannot. Some links can. Some cannot. Some links are trusted enough to pass ranking signals to another page. Some are not. YOU NEED LINKS FROM TRUSTED PAGES IF YOU WANT TO RANK AND AVOID PENALTIES & FILTERS.
Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.

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.
There are a lot of definitions of SEO (spelled Search engine optimisation in the UK, Australia and New Zealand, or search engine optimization in the United States and Canada) but organic SEO in 2019 is still mostly about getting free traffic from Google, the most popular search engine in the world (and almost the only game in town in the UK in 2019):

An SEO audit should not be rushed. It simply takes time to uncover root causes of the issues affecting your online health. Depending on the size of your site, a proper audit can take anywhere from 2-6 weeks to complete. Due diligence is required when making major changes to any website, and an SEO specialist must conduct a thorough investigation to make accurate, impactful recommendations.
How you mark up your images can impact not only the way that search engines perceive your page, but also how much search traffic from image search your site generates. An alt attribute is an HTML element that allows you to provide alternative information for an image if a user can’t view it. Your images may break over time (files get deleted, users have difficulty connecting to your site, etc.) so having a useful description of the image can be helpful from an overall usability perspective. This also gives you another opportunity – outside of your content – to help search engines understand what your page is about.
QUOTE: “Search engine optimization is often about making small modifications to parts of your website. When viewed individually, these changes might seem like incremental improvements, but when combined with other optimizations, they could have a noticeable impact on your site’s user experience and performance in organic search results.” Google Starter Guide, 2008
Site. Migration. No two words elicit more fear, joy, or excitement to a digital marketer. When the idea was shared three years ago, the company was excited. They dreamed of new features and efficiency. But as SEOs we knew better. We knew there would be midnight strategy sessions with IT. More UAT environments than we could track. Deadlines, requirements, and compromises forged through hallway chats. ... The result was a stable transition with minimal dips in traffic. What we didn't know, however, was the amount of cross-functional coordination that was required to pull it off. Learn more in this video!