We did a slow vinyasa flow each morning, plus a few other poses. Here are the things that worked:
1. Keep it short. Aim for 10-15 minutes, but let the children's attention determine the length of practice.
3. Describe the poses and the transitions between them, with as much detail as possible. Be ready to stop and assist when ever they ask. Encourage them to implement your yoga "suggestions" in what ever way they interpret them...as long as it's safe!
4. Liken the poses and movements to animals, or other creatures. Be ready to explain or laugh at the names of poses! Acknowledge and celebrate the names and comparisons they come up with.
Lots more great ideas in the BodhiKids portion of Bodhi Teacher Training.