With the new heroics leaning more towards controlling adds and using CC it's important to know how to setup a pull correctly as a tank. This can almost be as important as the pull itself. Sometimes when I'm on my warlock, I'll even volunteer to setup the pulls if the tank hasn't been to the dungeon before. Nothing beats pure experience but Blizzard always gives you hints with their naming conventions.
I'll use The Vortex Pinnacle as an example;