Not sure where I picked up this, but I’ve added this to my global Git ignore:
attic
That way you can just create an attic directory in any project where you can keep random stuff that should never be committed. I’ve yet to find a repo which actually has such a directory checker in.
~/.config/git/ignore and ~/.config/git/config is the proper place for your global git config and ignore instead of creating a ~/.gitignore_global and changing the config. IMO.
my dotfiles are a lot smaller at the root level taking advantage of the ~/.config/ for a lot more things.
the git exclude isn't used as much because it doesn't get committed to the repository so you'd have to recreate it each time you wanted to use it. that doesn't mean they're bad just why they are not used.
I use the ever living hell out of .git/info/exclude. Works great for scripts/Makefiles I only want locally and collaborators wouldn’t care about or be able to use.
Usually when I'm working in one part of the codebase and I have sample data or something at a specific path on my local machine and Im testing the same thing over and over again will I make a Makefile or something and info/exclude it to help me keep focused. That's one way I use it.