Don't be afraid of repetition. At times the kids may not always like it, but there are many things the kids don't like that are good for them.
The younger age kids love repetition. They love to know that they know something. The older kids also like to know that they know things, they are just bored more quickly with them. Be creative. I often take a Bible story and just rewrite it as a modern day skit or puppet skit. It allows me in a sense, to tell the same story twice, and if you are creative enough, the kids don't even realize it.
Reviewing is also a great way of repetition. My kids know that at the end of the service, right before my little sermon, I will pull out the candy and begin to quickly ask questions about the Bible story, memory verse, skit and puppet skit we have done for the day. I ask a question, and then give a small piece of candy to one of the kids who answers it correctly. This not only reinforces what we have done, but it also sets up the sermon that I give to the kids. Then to top it all off, if we have time, we play a game and go over the things we have learned again.
Peter says in II Peter 1:12-15 that he
continually put the people in remembrance of God's truths even though they
already knew them and were established in those truths, so that when he
would go on to be with the Lord, the people would have those truths firmly
and deeply rooted in their minds. In the same way, we in the Children's
Ministry need to continually put our kids in remembrance of Jesus and His
truths, even though they think they know it all and are established
in those truths, so that when they leave our Children's Church or Sunday
School, they will always have these truths firmly and deeply rooted in
them, and be able to stand strong in the faith of their Lord and Savior