Instead of making the standard El Numero with the numbers one through six make the numbers go up to twelve. In the area that you supposedly draw a circle instead draw a clock face with the numbers going around and no hands in the center. Now you have them think of any hour and then you mime drawing in the hands... here's one cool move: you really overact the twelve o'clock hand because that is always going to be drawn in then obscure where the hour hand is going.
Now start pulling out cards one at a time until the say STOP and turn the envelope around to show that you draw the proper hands pointed to the right time.
I made a sample set in about ten minutes and it works pretty good. It needs a little tweaking because the envelope is not quite the right size for all twelve cards and the backing they need, but by pressing my fingers against the sides and pushing from the back I can press the clock hands quite nicely and it looks good from a short distance.
I'm sure you crafty guys can make a better set so it's just a different way of presenting it and makes more sense.