Content is two-fold. It has to be engaging for the reader and understandable to computers and search engines. You want to rank but you also want to be engaging when you do rank, which will happen with enough content at some point. So, here's my answer:
Most Important Technical:
1.
<h1> - </h6> tags; for important rank-desire titles - order them chronologically
2.
<strong></strong> and / or (CSS): {font-weight: bold;} for important words - don't use in-line CSS that much
3.
<a href="someplace.html">Keyword Here</a>; put link keywords in your site and outside of your site
4. > than 600 words per article
5. Schema Tags; learn about schema mark up here:
http://schema.org/docs/gs.html#microdata_how
6. Sitemap.xml File
7. Robots.txt File
8. Rewrite URL to create vanity links in your site in your .htaccess file
9. Try to disguise .php extensions (not a huge deal yet)
10. Ease of Use: Responsive for mobile and tablets, anticipate swiping and fingers
Non-technical Content Factors:
1. Contrasting color scheme: light or white background on dark text is easier to read than white text on a dark background
2. Colors: off-greens, light blues = trust & reassurance, black, #1f1f1f = expense or power and luxury, red = raised heart rate
3. Engaging content: Have a "voice" and an opinion in your content. At least be yourself.
4. Large Titles: for easy reading on multiple devices
5. Listify: Written content is easiest to digest when it comes in the form of a numbered and titled list - like this post