Sure, the one I was thinking about is a tendency to strum really really hard, and you would think this would be an easy habit to break, but it is surprisingly difficult.
I remember seeing a Paul Gilbert instruction video a while back where he talked about the importance of being able to play a single note, while hitting it with a full on rock and roll windmill arms technique. This is mostly a matter of muting the other five strings effectively. But hitting a note like you mean it really matters.