Earlier this year I found this landscape photography youtube channel and I cannot recall the channel's name. I distinctly remember watching a few of his videos where he would go out in his van and camp overnight in certain locations to get early morning shots. He had a video about photographing in fog and stuff.
He did mostly digital, I believe he used Fujifilm and Nikon equipment if it helps narrow it down. And I distinctly remember him selling annual calendars or photo books. And no he was not Nigel Danson, I checked. He sort of had Sean Tucker vibes but slightly more upbeat.
I remember him being British or something. He had a few videos about him doing a road trip to Sweden or Finland to buy a Fujifilm TX-1 film camera from a fan. I particularly enjoyed that video and wanted to re-watch it, but I can't find it for the life of me. Did I just imagine this whole thing? I am losing my mind trying to find him.
To the best of my knowledge all non-volatile flash memory goes bad eventually. It cannot be prevented and can happen without warning. I suggest marking them with the date they were first used and just get rid of the old ones after a year or two if you use them heavily. It's a bit of a waste to throw out stuff before you know it's gone bad but it's pretty minor if this is how you make a living.
Also, a camera with multiple SD card slots can help. If you don't have one of those, buy multiple SD cards and just swap them out during the day. If one fails, you only loose so much.