touch ~/.gitignore
git config --global core.excludesfile ~/.gitignore
#Create your global ignore file like a normal .gitignore
#in your home folder.
git config --global core.excludesfile /path/to/home/.gitignore
#Your git now exclude any file declared in that .gitignore
#It's useful for hide your IDE's folder (.idea, .vscode, ...)
$ cd ~
$ touch .gitignore_global
$ git config --global core.excludesfile ~/.gitignore_global