"One two Three, Eyes on me" (me)
"One, two, eyes on you" (them)
"I'm on one, the counting has begun
I'm on two, where are you?
I'm on three, where should you be?
I'm on four, just one more -
(counting down seems to work better than counting up)
Put hands one either side of mouth and do stage whisper "freeze please"
(simple but it works)
touch a wind chime, ring a bell, turn on a music box, or use a cordless doorbell (button's in your pocket)