On the second pass I shave across the grain (from ear to jaw and across my chin). Like others I pull the skin up and shave following the jaw line. When I do my neck on this pass I use a scything(arcing) motion that starts just above the freshly shaved jawline and ends at the base of the neck. I shave the chin the same way, only i just concentrate on that area. The same kind of motion you use when peeling an apple.