I got this from an old HN comment I can't find anymore. I have this in my .bashrc:

  alias dotfiles='git --git-dir=$HOME/.dotfiles --work-tree=$HOME'

And I init my dotfiles into a fresh home directory like this:

  git clone --bare gitolite3@example.com:dotfiles $HOME/.dotfiles
  git --git-dir=$HOME/.dotfiles --work-tree=$HOME config status.showUntrackedFiles no
  git --git-dir=$HOME/.dotfiles --work-tree=$HOME reset --hard