Creative (and somewhat advanced) Photography Tips:
Have you ever noticed that part of your image is blurry, especially when photographing children? Maybe it's their hands or their feet that are blurry because they were moving? Most babies and children, unless they are asleep, are constantly moving. As a matter of fact, we typically get the greatest portraits when we let them move, shake, and be happy don't we =)
So another solution to this issue, versus trying to make them "hold still", is to put your camera on Shutter Priority, on a Canon it is usually the letter "T" and on a Nikon it is an "S" and now many hand-held cameras even have this option. Now move your sub-command wheel and watch the numbers changing. You are changing the shutter speed and your camera automatically changes your Aperture setting to expose the image as best the camera can.
Now what number do you want your shutter to be at? Well if you want to freeze the motion of those moving hands and legs I would say to have the shutter on 250 or higher. If you want to show the motion, say you want to see a bit of that movement as a creative blur effect, then I'd say you want a moderate shutter speed. Start at 1/30s and change the shutter number down until you achieve the desired amount of blur you are looking for. **You may need a tripod for these longer shutter speeds. This blur effect is also how you would achieve that dreamy blur of a waterfall if you find yourself at a beautiful waterfall in Hawaii at some point =)
So go ahead, put your camera on Shutter Priority and take control of your blur!