Over your time with a Cli you get to know the shortcuts and useful but lightly published commands and shortcuts to proficient and fast access to info you need when trouble shooting. The following link to firewall.cx is a greate article bring a wide ranging subset of these most useful commands all tougher in one place.
My team took part in a couple of Chaos days in getting ready to support the first fully in house production work load on AWS. This has resulted in our partner Cloud Reach putting out a blog on the experience of facilitation of the chaos! This also resulted in some further press articles below.