Google's official position on webmaster best practices really hasn't changed much over the years. What has changed is the search engine's ability to enforce these guidelines through improved algorithms. The implementation of Panda, Penguin, and Hummingbird has had a profound impact on the SEO landscape.
Google's Matt Cutts has remarked that no one should be surprised when a website that hasn't followed the guidelines is penalized. What Cutts overlooks or chooses to ignore is something that I have dubbed the "Google Paradox". I suspect the Google paradox is the root cause for one black hat forum member expressing his desire to "punch Matt Cutts in the face" (per Cutts' Pubcon 2013 keynote).
In order to reach the top of the SERPs and stay there in 2013 and beyond, your website must deserve to be there. It needs to be the best in class. It must offer the best user experience in that niche. Fortunately, there are a number of free tools that can help you achieve that goal.
Keyword Research
Developing the right list of keywords remains a staple of SEO, even in 2013. Because the keyword selection has such a profound impact on the overall performance of a website, the keyword selection process shouldn't rely on a single tool.