If you are looking to take your own portraits of your children, here's a quick visual guide to the main three standard types of shots you can take. Within these basic types you will have a considerable amount of variation available on each one depending on where you place your subject and where you shoot from, so hopefully this will simply act as a jumping off point along with a little bit of inspiration.
The first up is the Head Shot. In this composition, you will have in the head, and usually the shoulders in the frame. Generally speaking you are looking to get the eyes as the main focal point. Although eye contact is not absolutely necessary, the eyes do help to draw you into the image. In this shot below, those beautiful eyes are definitely the main focus. This was taken at F3.2, which blurs out the background so that there are no distracting elements that might pull the eye away from that gorgeous little face, and keep the eyes sharp and clear.
In this second shot, the eyes are again the focus, and it is a much tighter crop - if you do decide to chop off part of the head, make sure you do so in a way that looks deliberate, so no just skimming the top of the hair for example.
Here is another example of a head shot, but this time with no eye contact. If you go down the no eye contact route (either deliberately or because the little blighters won't look at you) you preferably need to have a strong emotion or feature that will draw you in the photo instead.
The next type is the partial or half body shot. When cropping at the body you always try to crop at a fleshy part of the body, and not at a joint, such as the elbow or the knees. Also, if there is a hand in the frame, try to include the whole hand and not accidentally chop the tops of fingers off - this goes for any body part! In this image below, I should have stepped back just a smidgen, so that i didn't slice off part of her shoulder or elbow (small as it is) but apart from that it's a good example of a partial body shot.
In this example, had my subject on the ground to include the top half of her body only.
Agan - eye contact is not necessary, but still try to have more going on in the frame to make up for that lack of eye contact. In this one, I do wish her arm wasn't chopped off at that angle (elbow!), but I think that the light, movement and expression allow me to get away with both the lack of eye contact and the slightly awkward chop.
Last up is the full body shot which is also fairly self-explanatory! When going for a full body shot, make sure you get all the appendages in - feet not clipped off at the toes, elbows in shot etc The subject doesn't need to be standing, they can be sitting or lying down too!
Again, eye contact is not always necessary to make a statement and draw you into the picture - when we don't have eye contact we alter the mood of the photo, changing the viewer into being more of an an observer - its up to you as the photographer to decide the mood or feeling you want the portrait to project.
You can also choose to show more of the environment in a full body shot, to give a sense of place and context, or just to show more about "who" your child is, rather than simply what they look like.
That was a very quick visual guide to the three main portrait types - as I said above, there is a huge amount of variation within these three, but it can be good to keep this simple mantra in your held so you can get a good range of images from one session!