Say Cheese? Pictures Gone Wrong

 This is more of what I'm hoping for when I ask my kids to smile for a picture. It's sweet, and cute, and very rare. I can only seem to get cute pictures of my kids inconsistently. What I USUALLY end up with is shown below....

I just have one thing to say. Telling your kids to 'Say Cheese!' DOES NOT WORK! If you don't believe me, look above!

So what I need from you people is a list of ways to get kids to take good pictures, and not one's where they look like they're in pain. So if you have some good tips, please share the wealth