What have been your costliest mistakes in using Linux?
For me it is not recording credentials with the assumption I would simply remember them later, while having every opportunity to archive them before eventually forgetting. Also, not keeping detailed enough notes & photos of exactly how my hardware is attached.
Before using dd, I prefer to run lsblk first so that I can see what each disk is called. Before pressing enter, I also double check the names with the lsblk output.
i love the raspberry pi imager for that reason. i don’t want no balena etcher stealing my data, but a gui is very convenient for flashing isos, so raspi imager it is! (works for any iso you want)