Nice article. You could expand on it by mentioning the config file.

For example, I have a remote proxy server, a different remote web server, github and so on, all with different user names and ports. I can alias each with their own setup, including adding an entry for a tunnel.

  Host    mymac
  ForwardX11      yes
  ForwardX11Trusted yes

  Host webserver
  HostName webserver.org
  User username

  Host myproxy
  HostName xx.xxx.xxx.xxx
  User aname
  Port 1934