At Interconnect 2015, I presented a demo showing how a team could quickly identify a lack of test environments, spin up a new one and then start deploying changes through that environment towards production. Since then, I've had a number of requests from people who didn't make the session to see what I put together. So I posted an informal pass through the demo to Youtube for your viewing pleasure. Enjoy.
For a longer write-up on techniques for eliminating environment bottlenecks, check out this article.