Well, I do it a little differently, I guess. I simply raise my arms to a side (usually the right arm risen at 90 degress while the left arm clenches it at an angle) and then I move the entire combination (of the two arms) over my head to the left. That delivers quite a satisfying crack, which eases out much of the stress in the neck region.

I am trying to avoid cracking my neck, and cracking the shoulders seems to be a safer option anyday!