How do you do cross curriculum with CM?

I am not sure I am doing this in the right way and I can’t remember how the CM mother’s at our SCM conference described their methods.  Can anyone shed light on how they teach multiple lessons/subjects with one living book?  And how do you keep it true to CM?  Are those lessons (taught within the context of another lesson) enough or do you plan to follow up with a more specific lesson in that subject area?