Here are a few of my "secrets."
1) I am new to them. Trust me... I don't get my own (very active almost 2-year old) to sit still and smile all that often myself. But when new people are around, he is more likely to hold a pose just long enough for his mama to click her shutter button and get a great shot.
2) I have a "Camera Critter" on my lens that looks like a very popular red character on TV. I cannot tell you HOW great this is... not only do the kids recognize him, but they LOOK at him while I photograph them. It's funny... in every shoot with children, I get several shots of the kid(s) pointing at the camera, because I always ask them, "Where is Elmo?" and they laugh and point and say "THERE HE IS!" Too cute. I love my job...