What do you have for ‘back-up’? Do you have a back-up camera, how do you back-up the images, etc?

Regarding digital back-up: My main camera body has a digital file back-up built into it in case one of the memory cards fails.  I travel with a 2013 MacBook Pro and an external drive, and I save every image to both immediately following the wedding (before I’ve even showered or unpacked from the day).  So, in addition to the memory cards themselves, the files are doubly backed up.  When I get home, I upload the photos to my Synology 15TB back-up system, which is also backed up by CrashPlan.  Phew.  Lots of back-up.

As for a back-up camera: I have two professional-grade Canon camera bodies, each top of the line for lifestyle photography professionals (Canon Mark III & Mark II).