Google’s Quality Guidelines – or Webmaster Guidelines – have long been a bible to the dedicated white hat search engine optimizer.
Straight from the big G’s mouth, below are the specific guidelines (correct March 2018):
Webmaster Guidelines – Basic principles
Make pages primarily for users, not for search engines.
Don’t deceive your users.
Avoid tricks intended to improve search engine rankings. A good rule of thumb is whether you’d feel comfortable explaining what you’ve done to a website that competes with you, or to a Google employee. Another useful test is to ask, “Does this help my users? Would I do this if search engines didn’t exist?”
Think about what makes your website unique, valuable, or engaging.
Make your website stand out from others in your field.
Avoid the following techniques:
Automatically generated content
Participating in link schemes
Creating pages with little or no original content
Hidden text or links
Participating in affiliate programs without adding sufficient value
Loading pages with irrelevant keywords
Creating pages with malicious behavior, such as phishing or installing viruses, trojans, or other badware
Abusing rich snippets markup
Sending automated queries to Google
Follow good practices like these:
Monitoring your site for hacking and removing hacked content as soon as it appears
Preventing and removing user-generated spam on your site
If you follow the above rules, and promote your website actively, as well as making sure your website is responsive, and, importantly, nice and fast, then you will do well in search, we trust.