I tried the boiling water method I had seen on here
from one of the brethren. My mate does not normally eat chicken skin, nor do I...but we ate all of it on the drum sticks. The method works.
+1 I try to give my chicken several hours in the fridge uncovered to let the skin dry out a bit. It is not a sure way to get the crisp, but it is a step in the right direction.
As has been said, if your smoking at low temps, the only way I've been able to crisp the skin is, after smoking, place the chicken skin side down and grill direct.