If there is anything that does not change with Google's mood, then it's this:
"Content is King"
However, one does not simply get 10 pages of high quality content every time Google decides to dance again.
In niches with high competition, it's impossible to rank with pure content.
I think that high quality backlinks are still getting much more important. Exchange links with similiar sites, you will not only get a good backlink but maybe some visitors, too.
And don't forget that social media gets increasingly important for ranking. Tweet and share your website as often as you can. I have seen minor improvements on some of my pages (#13 to #11) after tweeting a couple of hundred tweets with my url embedded. We had some threads about this, it's definitely worth reading.
Also consider stopping link building for a while. Google wants to see who panics.
kind regards,
SICK