We've recently upgraded our computer stock with a bunch of new (old) Mac Pros. These are the last computers which Apple built which can be upgraded (storage, memory, GPU, CPU in order of complexity). So I've updated our guide on deploying new Macs. I've often been asked about our special sauce for securing Macs and deploying them quickly so I've publishing this as a starting point for others.
Despite the title stating that this covers how to set up a Mac securely on OS X, it hasn't really been possible to secure a Mac since the App Store came into being (OS X 10.6.6 I believe). OS X 10.5.8 may be the last really secure full version of OS X ever created. Coincidentally Apple joined Prism in 2012.
Still one can make a good effort to make one's computer far less chatty. If you really want to be secure, don't use the app store at all and download your OS X updates. If you want to be a little bit secure, you have to avoid iCloud completely. Just ask the beautiful Jennifer Lawrence how iCloud turned out for her (I had no idea she was so sexy until those pics showed up).