Little ones don’t usually think sitting still for a picture sounds like fun. It may be possible to barter a few fleeting seconds (literally, seconds) with a two-year-old, but realistically, photography takes more time than that.
So. When I do a session with little kids, I don’t worry so much about getting them to hold still. I like to set them up in a situation and get them to play and have fun. It’s up to me to do whatever acrobatics are needed to capture the perfect moments that ensue. I shoot many frames to get a few, and when there are multiple people in an image, it is likely a composite of several original shots.
If you have a session scheduled with your kids, don’t stress too much about how they act when you get there. Straight out of the car and feeling pressure to “be good,” little kids probably won’t be able to sit still and smile for the camera right off the bat.
As a photographer, I expect this. The best way to handle the situation is, if they’re being silly, be silly right along. If they’re being reserved, capture that mood and give them time to get a feel for the situation. These are things kids do when they’re uncomfortable. A lot of times, that little bit of space held for them leads to them settling in and becoming a lot more relaxed.
Long story short, making beautiful images of little kids sometimes requires thinking outside the normal conventions of portrait photography. Let them be kids. Get them playing and laughing and then surprise them with a squeaky toy behind the lens. Let them run circles around you. Tell them about the bunny in the camera that they’ll see through the lens if they’re looking at JUST the right moment…
Your patience and forbearance (and the photographer’s skill in Photoshop lol) will pay off 100 fold.