The simplest path to great SEO is to study your competitors.
Enter the keyword within Google that you want to rank for then analyze the top results. Ask yourself, forgetting about search engines for a moment, why is this content great? Be prepared to invest this effort at the least to outrank them.
This is powerful since not only are the reasons complex, but ranking factors differ based on search query.
You may write a great blog, for example, only to find that Google prioritizes video for that search. Or maybe that query is best fulfilled with informational over transactional content. Perhaps they want an organized piece, with headers forming a list of tips, to display as a featured snippet.
A good SEO can help further by expanding upon just what better means, say more backlinks or something less obvious that differentiates a top result.
Here’s an extra tip… Bing Webmaster Tools now allows you to freely explore competitor backlinks!