The thing I work with on the most with practically everyone I coach is Content.  It’s difficult to know what works, because you can’t count on accurate feedback from the phone lines.  So here’s the simplest way I can explain it:

Anything you have in common with the listener that leads to some sort of emotional “reveal” is gold.

Now read that again.  No prep sheet item, no social media posting that lacks those two key ingredients – what you have IN COMMON with the listener, and an Emotion being revealed – will work as well without them.