Cross back two - decide ahead of time what the cross is, and your safety set is a back two... Normally outside hits a two and the middle hits a 32/31
Other things -- a "stack" is both hands closed as fists stacked on top of each other. Then do your signal for what thier hitting. (quick and a 2, 32/31)
One of my other quirks is not using my thumb in anything but a 31 (which you don't really need it to tell what the call is)... It's something i do normally to not confuse people, using your middle, index and thumb to form a three is odd - and can be seen as a two not a three from certain angles.
Now your only trouble is, is getting your hitters to SEE the call and pay attention in the 2 seconds you have before a serve.
Ok, class is out - any questions?