Cueing arch and flatten

Hi all,
I'm entering this as a forum discussion as part of moduel 1 assignments.
I've had some great experiences so far in my clinical sessions, I've done 10.
A few times I've had trouble cue-ing and getting people started with just the basic arch & flatten that I've taught for their homework and just after they are supine to use in the last few movements/pandiculations.
The "pelivs is a rolling pin" method that Nancy used in class I thought was great, but I have definitely stumped a couple ppl with that metaphor. The people I was working with eventually got it, one I had to demo myself and def something they knew they needed to work on more just to be able to do it.
Just wondering if some others have metaphors or descriptions they use that work for getting people to do the arch and flatten in a means-whereby type way, so they are really feeling it and not just arching their back.
Cheers!
Faith