We have been on rotation for nearly 7 years now and it's been a tremendous success.
1. We tie the children's sermon to the workshop lessons at least once a month and whenever else it's possible.
Most Bible stories are certainly good for more than one children's sermon!
After doing one or two children's sermon a month on the story we are teaching in our Rotation Sunday School, we tell our pastor to feel free to do children's sermons about THEIR sermon, or any of the other readings they are using in worship.
As well, we have given them a list of the stories we are NOT covering in Sunday School at all or this year, so that those stories can get covered in children's sermons if needed. For example, we don't do a four week Rotation on "David and Jonathan" but it's a good story for a children's sermon about friendship.
2. We have also suggested the pastor do some teaching about worship.
What is Communion, Baptism, why we sing hymns, etiquette, special words, candles, sermons, praying, etc etc.
These two things accomplish several important things:
1) It gives the pastor an opportunity to feel connected to our Sunday School and contribute to our rotation content!
2) It showcases that the children are learning (which makes the congregation see the value of our model).
3) By talking about our rotation lesson in worship, it reinforces and validates the importance of our lesson content in an important context.