When shall we cross ourselves?
Whenever we are about to perform a good deed, or when we see or feel that we might commit a sin.
This sounds like a great way to prime yourself. Crossing yourself has all the wrong connotations, but a gesture meaning "I choose good." should help in general. (I like the fist-over-heart Battlestar Galactica salute.)
Having a whole set of gestures, along with pithy quotes, should prove even more effective.
Their insignia was a hand poised with fingers ready to snap.
ETA: Or is that reserved for "I choose whatever they aren't expecting"?
Y'all know the rules: