Updated on Mar 13, 2019
Domain Character Length - Typically domains above 15 characters in length will look less trustworthy to search engines.
Domain Age - Domains that have been around for a longer periods of time tend to bring more trust than newer domains. This is because unpopular or irrelevant domains quickly disappear and domains providing important information are often tens of years old.
Domain Expiration - Search engines can take into consideration the time your domain has before it expires as soon to expire domains are more often used in untrustworthy activities. However, note that this is a very subtle marker and will not greatly affect the SEO of your domain even if you have less than a year until expiration.
Preferred domain set - Having both www and non-www versions of your domain can sometimes confuse search engines that the content is duplicated. To avoid this you must specify which domain you prefer by creating a redirection to it from its other version.
Canonicalize your IP address - Your website's IP should be redirected to the domain name you chose in the previous point. If not Google may thing that the IP and the domain are two different instances of the same website and that content is duplicated.
Robots.txt file found - In order to be sure which pages you want indexed and which you wish to keep hidden from crawlers, you must properly configure your robots.txt file.
Favicon found - Favicons are the small (16x16px) icons that appear when you open websites in your browser. It is a little detail that provides a bit of additional boost to your website's SEO. Make sure that your favicon image is correctly named - favicon.ico