When shooting kids, it is important to shoot a lot of different ways, to see what will work. Take a lot, and see what works, then refine that. Best to use simple studio lighting. I try to engage the child in the shoot, allowing him, for instance, to choose some of the gel colours.
Here’s a few from that portrait shoot this morning:
Kids move, so a nice prop (like a stool, in the example above) is good.
Do not be afraid to get close and fill the frame!
Try desat or otherwise changed colours in a few images.
And try different positions.
Simple backgrounds are good, because the emphasis should be on the child. But I sometimes just change my position to get a difefrent background, like the grungy one here:
Bribery helps, too!
If you do not have a studio setup, use a prime (fixed) 50mm lens and larger aperture and 1600 ISO indoors in reflected light. Either way, you will end uyp with good images. Do it – your child is young only once. And do also consider going to a pro – if you come to me, I will teach you some useful photography skills while we shoot!