One of the tough parts of photographing kids is that they get bored with it pretty quickly. You can ask most kids to "smile" about three times before they decide that they'd rather be chasing the dog or digging for worms in the garden. But most kids are really good at taking instructions (most adults should be so good!) and they also love a creative challenge. If you give them something interesting to do they will pretty much ignore your camera.
The trick is to find an activity that keeps them relatively calm and in one place, yet is also something they like to do and that also makes an interesting photo. You obviously can't ask an eight-year-old boy to climb a tree or you'll have to climb up after him to get a close picture. But there are lots of fun passive activities that work nicely--drawing with chalk in the driveway, coloring Easter eggs or even just reading a book out loud to you. Just be sure to set the shot up in an attractive area with good natural lighting so that you don't have to rearrange things once you start shooting.
You also have to put a time limit on the photography part of the session, even if they want to continue on with the activity--otherwise they'll start to get tired (of your camera mostly) and withdraw. My friend Alice was only four when I photographed her blowing this huge bubble and she'd never done it before! I was amazed (really amazed) at how good and patient she was a blowing bubbles and at how huge they were. After about 20 minutes though she let me know that photography was over and so we put the cameras away and just blew bubbles. There's a time for pictures and a time for bubbles and let's face it, bubbles are a lot more fun.
Tech Notes: By the way, you might want to know that the way I got the background out of focus was by using a combination of a moderately long lens (the equivalent of about 105mm in 35mm terms) and a small aperture (the lens was almost, but not quite, wide open at f/5.6). The combination of the long focal length and relatively wide aperture created a limited depth of field (near-to-far sharpness) and restricted sharpness to just her face and the bubble. When you do limit the depth of field though, be very careful to focus on what you want sharp. In this case I focused on the area around her nose and the bubble. I also worked close to her and that helped keep the background out-of-focus, too. And I chose a location where the light was fairly bright on the shrubs behind her so that the scene would have a light, airy feeling. I did do a bit of careful softening of contrast in Photoshop and I warmed up the colors a tiny bit. The scene is pretty much how it came out of the camera, however.
11 hours ago