I was going nuts looking at Bootstrap tutorials because they all say exactly what you can read in the docs, and none of them say the very important thing that isn’t in the docs, namely just which dependencies you need and the methodology involved to build it all when making your own theme.
So it was a huge relief when I finally found someone who very simply stated the actual steps involved in turning a mess of files into your own CSS. So massive thanks to Alexander Rechsteiner of hackerthemes who put this useful guide and kit together.
I believe I can now finally get to work on making a theme now. This had only been driving me crazy on-and-off for a few months now (most of that time spent not actually looking into it).