Before we begin, I'm going to be using a lot of snippets from Git's configuration file(s). I originally used BEGIN_EXAMPLE to render these as preformatted blocks, but after some research I discovered that the following code will create a new 'source language' with which we can view those snippets. 

(add-to-list 'org-src-lang-modes '("gitconfig" . "conf-unix"))

I found that mode's name by opening ~/.gitconfig and typing C-h v major-mode to view the value.

With my new job using GitHub for its development workflow, suddenly maintaining a separate work identity in Git matters. Since we have dozens of repositories, setting my identify in each one was getting very tedious and error-prone. Git now has a feature that permits including files into its configuration based on the directory of the repository. This by having the following within my ~/.gitconfig: 

[includeIf "gitdir/i:~/go/"]
      path = ~/.gitconfig.work

Note the use of gitdir/i, since I am on a Macbook which I just discovered treats path components in a case-insensitive manner, so we use this instead of gitdir just in case. The contents of ~/.gitconfig.work are: 

[user]
      email = <my-work-email>

Additionally, there are some files that I create locally (e.g., TAGS) that I do not want to be considered by Git. Adding these to each repo sucks, so I'm now taking advantage of the following in ~/.gitconfig, which does just what it says on the tin: 

[core]
      excludesfile = ~/.gitignore.global

Finally, some of the setup scripts I've been running into try to clone private repositories from GitHub over HTTPS, requiring usernames and passwords. Since I'm a firm believer in the user of SSH keys whenever possible, but don't want to (or don't have the power to) fix all these scripts, I have found another handy Git feature that forces specified transports for certain hosts: 

[url "git@github.com:"]
      insteadOf = https://github.com/