Most sensible Compiler flags aren't enabled by default... I keep a list of arguments for gcc to make things better, but even then you'll also wanna use a static analysis tool like clang-tidy
Sure, I put quickly put them into a small markdown file.
At my job we have a cmake interface target that handles these (along with some version checks and project specific stuff), but I can't publish that of course. I might put these into a cmake file at some point, not sure.