i daven in a shul in yerushalayim where there are many children watching the leining, davening, answering amen yehai shemey rabba…one of those children is my five year old bayis brother (i’m a bas bayis at his family). there are also girls who come to shul – there are three sisters who sit in the row next to me between the ages of like seven and ten. they sit (or stand) quietly and daven.
there’s something these parents are doing right and i’m not sure what it is. these children are not only quiet during shul, they participate in the services!
(i’ve been with the shul for a pretty long time by now and the ONLY time i’ve been disturbed by a child was when a mother brought a three year old (for heaven’s sake!) with her to r”H mussaf and the kid was jumping off the seat and making the floor shake. but he wasn’t even talking or screaming or anything!)
my own idea is when the children see the father or mother excited and happy to go to shul and are told before what the rules are (like mamashtakeh said), and see how the parents act and how they consider shul, they’re much more likely to act like the children in my shul.