My approach is typically to follow some kind of a guide or tutorial and to look into the man pages or other documentation for each tool as I go, to understand w

My approach is typically to follow some kind of a guide or tutorial and to look into the man pages or other documentation for each tool as I go, to understand what the guide is suggesting. That's how I handled things e.g. when I needed to resize a partition and a filesystem in a LVM setup. Similarly to your RAID example, doing that required using a bunch of tools on multiple levels of storage abstraction: GPT partitions, LUKS tools, LVM physical and logical volumes, file system tools. I was familiar with some of those but didn't remember the incantations by heart, and for others I needed to learn new tools or concepts. I think I use a similar approach in programming when I'm getting into something I'm not quite familiar with. Stack Overflow answers and tutorials help give the outline of a possible solution. But if I don't understand some of the details, such as what a particular function does, I google them, preferring to get the details either from official documentation or from otherwise credible-sounding accounts.