As important as links and publishing content remain, search engines are growing far more comlex that relying on traditional text and document analysis to rank its index.
Followling the best practices is pointless, unless you're following all of them.

1.Content

91% percent of online content generates no traffic from Goolge, research by Ahrefs.

Content Relevance to User Intent
Understanding User intent is the future of search engine development.

How to Optimize

• Understand the intent of your keywords.
• Analyze the SERP of these keywords and what type of content is
  ranking.
• Research semantic similarities to that keyword and optimize content
  around those terms.

Deep Content
A HubSpot study found that content between 2250 and 2500 words tended to receive the most prganic traffic.

How to Optimize

• Research top ranking pages for a target keyword and analyze their
  content.
• Add semantically related keywords to flesh out content with
  additional sub-topics.
• Answer any and all questions users may have about that topic.

Organized Content
Hot to Optimize

• Insert focus keywords into title tags, URL slug, and page titles.
• Create header sections(H2,H3,H4s) using related keywords.

2.User Enagement

User signals can be a good indicator of improements tht you need to make on your website.

Pages per Session
The Pages per Session metric indicates how many pages a user views before leaving your site.

How to Optimize

• Analyze pages with high bounce rates and search for opportunities to
  encourage longer session durations or more pages-per-session.
• Insert calls-to-action on pages to encourage conversions.
• Provide additional navigation options within content, such as placing
  interlinks in body content or providing related reading materials.

Bounce Rate
The bounce rate indicates ho satisfied users are with your landing page or website.

How to Optimize

• Tell a story or lead with a compelling hook.
• Get rid of instusive interstitials and pop-up advertisements.
• Improve page load time.
• Ensure loading page copy is relevant to search queries.

Click-Through Rate(CTR)
Tips to Optimize

• Insert exact match keywords into title tags and meta descriptions so
  they are bolded.
• Add a benefit of clicking on this page(e.g.,"BOGO")into your meta
  description.
• Ensure your tags are the proper length so they don't get truncated.

3.Technical Structure

Technical SEO could be considered the foundation of SEO where everything else is built on.

Crawlability
Tips to Optimize

• Create asitemap and submit it manually through Google Search Console
  and Bing Webmaster Tools.
• Block all pages you don't want crawled or index by placing them under
  the disallow file of your robots.txt file.
• Clean up redirect chains and set parameters for dynamic URLs.

Security
Having an HTTPS secure is a soft ranking factor for Google.
While pages should theoretically redirect to their HTTPS counterpart, it still isn't advantageous to have links to mixed content. More inportantly, these links do not always redirect.

How to Optimize

• Set SSL for you webiste
• Run a crawl of your website using Screaming Frog to identify mixed
  content errors.
• Place stemaps in your robots.txt file.
• Rewrite you .htaccess file to redirect all website traffic to a
  specific domain using the HTTPS URL.

Clean URLs
Generally, you want clean URL structures with status 200 codes.

Tip to Optimize

• Run a crawl of your website using Screaming Frog to uncover 4XX and
  5XX status codes.
• Use 301 redirects on broken pages to send users to a more relevant
  page.
• Implement custom 404 pages with available URLs to redirect traffic to
  relevant pages.
• Contact your web host provider for any 5xx errors impacting URLs.

4.Inerlinking

If technical SEO if the foundation of a website then internal links are the doors that allow you to move from room to room.

Deep Links
Tips to Optimize

• Conduct a crawl to identify orphaned pages that are not being
  indexed.
• Use links strategically within content to pass along authority and
  provide
• additional reading content(2 minimum per post).

Organized Hierarchy
Generally, your hierarchy should be designed from a top-down approach, allowing search engines to crawl and index certain pages under buckets or clusters.
Tips to Optimize

• Conduct user research to see what customers are searching for.
• Use exact match keywords to optimize category pages and ssemantically
  related keywords for sub-category pages.
• Add breadcrumbs or links in footers for users to navigate back to a
  specific page.

5.Mobile Responsivity

The mobile first index has become Google's primary ranking index, meaning it is updated before its desktop index.
Long-scrolls are preferable to links that force users to load another page and impede their surfing experience.
The two most important mobile factors include mobile-friendly design and fast page speed.

Tips to Optimize

• Implement responsive web design
• Tag pages with AMP code using your CMS.
• Improve page speeds by minifying onsite resources.

Conclusion

SEO is a dynamic and organic industry and by looking at it from a more holistic point of view we can better serve our users and survive changing algorithms.

Link:https://www.searchenginejournal.com/on-site-seo-factors/295357/#close