I wait for them.
I'm in no rush, even if I'm personally going "Wow can you hurry please"... especially if they are new.
When I was learning tanking, I certainly wasn't new to the dungeons but I was new to tanking and this would anger me to no end, especially the first time tanking a dungeon.
Just. Wait one second. Not worth stressing someone out and having them lose aggro to kill and wipe everyone when you could have taken a breath and wait.
