I thee undo
For years I've been using C-x u (undo) for undo. As much as I use it,
though, I really need to get C-/ (undo) under my fingers.
I never remember revert-buffer, since I rarely get myself to the point
where I want to just nuke everything from orbit---so perhaps it's not
surprising I rarely think about it.
In fact, I think the interface of GNU Emacs' undo facility is one of the few places where it falls dramatically short of its potential. I really don't know what sort of facilities that other editors have, but given the way that Emacs stores the history, I'm surprised that the baked-in functionality provides no way to access it more efficiently---I mean, there's not even an explicit redo command, you have to just undo your undoings, ad infinitum. I've often accidentally started redoing things when I hit an injudicious key, etc.
Poking around EmacsWiki, I find a reference to UndoTree, which looks like just what I might like. Perhaps I shall package it up and see how well it works. If so, I'll report back.