Here is thread on head-TURN trick, where dog poses with his head to the side:
http://www.dogtrickacademy.com/members/forums/threads/trick-challenge-show-us-your-good-side-trick-super-easy.4196/
but that is NOT what you asked for.
I
had tried this "head-cocking" trick in the past, holding a squeak toy behind my back,
squeaking the toy, and of course, my dog cocked his head at the odd noise,
CLICK/TREAT,
but my dog never did get it, so maybe this is NOT how to teach it........
or maybe i gave up too fast and moved on, but it's been a year,

i guess it'd time to try it again, right?
I was using the cue word "money" for the trick, and then my dog would cock his head to any question that ended with "money", like, "Buddy, do you want money?"
or "Buddy, who is going ot pay? Do you have any money?"
and so on. (for questions, only use the LAST word, or else dog turns their head too fast, before you have finished the question)