Its amazing that after having read probably hundreds of Vim tutorials / guides every user is able to learn something completely new from every one of them.
It sure scales.
This one brought ^T and ^D for indenting in insert mode to me, and starting with -o/O as argument for opening multiple files in splits.
also, ciw which I use far more often than cw (don't need to be on beginning of word to change the whole thing). I like how all the ci commands always elicit a "whoa, what did you just do?" from people watching me edit.
It's this kind of magic that attracted me to Vim in the first place. I watched a professor doing that stuff in front of class and my jaw dropped. The circle was complete when a coworker watching me modify some code had a similar reaction. (Sadly I did not convert him.)
This one brought ^T and ^D for indenting in insert mode to me, and starting with -o/O as argument for opening multiple files in splits.