In spite of what you may have heard, not that much. SEO today is still based on 2 main things:
On page content ( must be relevance to search phrases and be of good quality)
Quality backlinks from other websites pointing at your page.
What are Backlinks?
Backlinks, are links pointing to your website from another site. Inbound links were always important, what has changed however is the quality of links pointing to your website. The number and the quality of backlinks are one of the factors considered by Google to determine where to rank a site.
Other factors that come into play are:
How much traffic is your site getting, and
Social signals (Google Plus, Twitter, etc.)
In other words, SEO is pretty much the same it always was. However, what has changed is how we get the "right" backlinks. Gone are the days where we could just drop thousands of links via syndication tools anywhere and anyhow. Now we need to focus on relevancy (how does the host site relate to your site?) and quality (authority site vs junk site), according to Google’s algorithm.
There are several factors that determine the value of a backlink. Backlinks from authoritative sites on a given topic are considered highly valuable. If both sites have content geared toward the keyword topic, the backlink is considered relevant and believed to have strong influence on the search engine rankings of the web page it points to.
A backlink represents a favorable 'editorial vote' for the receiving webpage from another granting webpage. Another important factor is the anchor text of the backlink. Anchor text is the descriptive labeling of the hyperlink as it appears on a web page. There are different classifications of anchor text that are used within the search engine optimization community, such as:
an anchor that is used with a keyword that mirrors the page that is being linked to. Example: "the wall street journal" is an exact match anchor because it's linking to a page about "search engine optimization.
a generic word or phrase that is used as the anchor. "Click here" is a generic anchor. Other variations may include "go here", "visit this website", etc.
whenever an image is linked, Google will use the "ALT" tag as the anchor text.
You should have a diverse portfolio of anchor texts. To get information of your site's backlinks, anchor texts, and a host of useful information you can go to: https://majestic.com/.
A word about quality content
Realize, content is for humans, not for spyders and bots. Strive to fill your pages with super, high quality, informative content related to the products and services you offer on your site. Make sure it is content that people want to read. If you can get this content right, and apply the backlinking and relevance, ranking at the top of Google is now easier than it ever was before!
My best SEO tip for today is: Develop a Content Strategy, it will attract high authority, natural backlinks, and social signals, and boost your rankings to the top!