The way I was shown, and this seems to work fairly well across those of us in the Stumptown herfer group, was to draw off the cigar, tilt your chin down to your chest, and then gently attempt to push your tounge towards the roof of your mouth (think of the motion like trying to push the smoke to the back of your throat). It should come out your nose in a gentle fashion.
Also, try this (initially) on really mild smokes. I did this with a Pepin the first time and let's just say it hurt for a while.
Thanks to vstrommark for this advice!
