Before working with databases, I was an applications developer, so I have a solid understanding of general software engineering principles (particularly, the IEEE CS SWEBOK.) The general concepts apply across all software, whether it's desktop, web, mobile, or databases. This knowledge helps me determine if a “best practice” I find somewhere makes sense or if I should keep looking. It's also imperative to keep learning, to test new ideas before implementing them, and to readily change things that aren't working.

It surprises me how many DBAs aren't familiar with even general SE concepts such as the software development life-cycle. I think all developers would benefit from spending some time working in a new area: DBAs to try app development, web developers to try desktop work, etc. But, I know that's wishful thinking for many people. I've been lucky in having the opportunity to do so.

So in answer, I don't have a single oracle I consult. I prefer books over blogs because the tend to have more editors but that's not always reliable. Ultimately, I depend on my understanding of SE and my cross-training to help me triangulate good information from the cacophony of ideas and opinions available now.

And, I always test something new. That's probably not even worth saying here, but you never know.