If like me, and a couple of others I’ve spoken to recently, you were not previously aware of “sudo -i” then you might be interested to know that you can save yourself two keystokes by switching from:
sudo su -
From the man page:
Run the shell specified by the target user’s password database entry as a login shell. This means that login-specific resource files such as .profile or .login will be read by the shell. If a command is specified, it is passed to the shell for execution via the shell’s ‑c option. If no command is specified, an interactive shell is executed. sudo attempts to change to that user’s home directory before running the shell. The command is run with an environment similar to the one a user would receive at log in. The Command Environment section in the sudoers(5) manual documents how the ‑i option affects the environment in which a command is run when the sudoers policy is in use.
Simple, but useful if you’re someone that enjoys the quest to reduce keystokes.
 – This post was originally written about “-s”, but as pointed out by Paul in the comments this is not equivalent to “sudo su -”.