What are the best ways to increase your site's position in Google?
Any google search for anything about SEO yields more articles than you can shake a stick at, but lot of the articles are out of date, many have conflicting advice and I just about none of them ever give any reasons/proof/data to back up their claims about what works and what doesn't.
Has anyone done any at least somewhat scientific tests to see what works and what doesn't (and ideally why?) or has anyone from Google released any non-basic information about best practices?
Really what I would love to do is A/B test different SEO techniques, but the time lag and sheer number of variables makes it very difficult. Has anyone ever tried this type of thing? (And published their results?)