Good one. And now that I think about it, let's not forget the basic slap. Very useful for a variety of things, not least of which is ending a fight through humiliation.
Truth enough with that. A nice hard open handed slap across the face is a nice starter or stopper. As a starter you have as much of a psychological pause button as much as a first strike. It's a great way to start things & a great opener. Move it back from the face a smidge & into the jaw/ear area... nice love tap there. Not to mention the concussive impact that the open hand carries...