I have two children (ages 2-4) who are just getting old enough to know when to make the worst possible face or simply run away when I bring out the camera.
Does anyone have any tips on how to get children to cooperate better for photography?
It is very highly dependent on the personality of the child. What works wonderfully for my daughter (Positive Feedback) may not work for other kids. So it helps if you already have a good handle on working with the child. With that said, here is what works for me:
Give the Child Options
Engage in Pretend Play
Patience, Patience, Patience
I would make the experience fun and exciting for them. Show them the camera, let them take a few pictures. If you let your children take a few photos here and there, they'll feel a lot more comfortable around the camera. They might even develop an interest in photography. You should answer the questions that they have and show them how it works. It might also help if you let them take a few pictures of you when you take photos of them. It also depends on your children's temperance. Maybe you could ask this question on a parenting forum (Do they have a SE for that?).
A few quick tips which I have found useful: