I usually wave my arms around. "Men on THIS side. Ladies on That side."
It annoys me when callers say "take inside hands with your partner and face up". Its only the inside hand AFter you've faced up.
And "Ones are improper" (no, they're not, should they be?).
And anything thats said to everyone when it only refers to the men.

It is amazing how dancers can find another meaning for anything the caller says,when I thought I was being perfectly clear. (Well I knew what I meant!).
And trying to remove one ambiguity can introduce another. It annoys me when callers say "lines facing up and down" (well, should my line face up or down?). But "lines facing away from each other" produced lines on the side.

Then again, if you try to spell out every detail people stop listening cos theres too many words.

We can only do our best, admit to our mistakes (if the dancers go wrong it's always the caller's fault for not being clear), and try to keep it fun.