I don't have to tell you, one never snaps one's fingers on the beat. It's considered aggressive. Don't push it, just let it fall. And if you would like to be respectably hip, then at the same time tilt the left earlobe. Establish a state of nonchalance. And if you would like to be respectably cool, then tilt the left earlobe on the beat and snap the finger on the after beat. And then, you really don't care.