If you have not come across Proost before, these stunning videos from John Birch (who also happens to be a friend of Dan Jones) are a fabulous resource and suitable for both children and adults.
Why not play them and have a discussion with your children/youth group or play them before the service (or during your sermon) this Christmas time. Check out the first one for free on Youtube via this link.
Enjoy!
http://www.proost.co.uk/altadvent