git

Tell git who you are.

$ git config --global user.name "Ash Williams"
$ git config --global user.email "ash@s-mart.biz"
$ git config --global init.defaultBranch "main"

[source]

Verify the commands above created a ~/.gitconfig file.

$ cat ~/.gitconfig

Add a few useful aliases to ~/.alias.

alias ga="git add" # usage: ga filename
alias gc="git commit -m" # usage: gc "commit message"
alias gs="git status" # usage: gs
alias gr="git reset"
alias grh="git reset --hard HEAD"

Other git configuration commands:

# show current configuration
$ git config --list
# configure pager to exit if output is less than one screen
$ git config --global core.pager "less -FR"
# create a global .gitignore using gitignore.io
$ curl -L https://www.toptal.com/developers/gitignore/api/ruby,node,linux -o ~/.gitignore
$ git config --global core.excludesfile ~/.gitignore

If you need to manage git settings by folder, read about how to use Conditional Includes from within your ~/.gitconfig file.