On the subject of tech hardware backups...
I go down to Devon by train to visit my sister 4 or 5 times a year. I used to get paper tickets but have now started using e-tickets. I worried about what I would do if my phone played up so I couldn't show the e-tickets. I would be mightily peeved if I had to buy more tickets, having already spent over £100! I could print out the tickets at home, but that would make e-tickets rather pointless...
Then it dawned on me that I always have my Android tablet with me on those trips. I now make sure that I have backup e-tickets on the tablet, just-in-case.
The other hardware backup that I resort to is when doing a long ride on unfamiliar roads. My Garmin has been very reliable, but I would hate to get lost if it were to die mid-ride. I therefore keep a copy of the route in the Memory Map app on my phone. I haven't had to use it yet but it is there if I need it. It is also nice to be able to check progress on the app's OS map - the ancient Garmin doesn't have maps, just displaying routes as a squiggly 'breadcrumb trail'.