My toughest is that "first thing in the morning smoke". I have found that it was the flavor....that harshness of a ciggy on a clean palate.......I now put a strong coffee flavored carto on my 808 and that is what helps me for that morning craving.....
My nic is 18....sometimes 24, but it depends on the flavor....some flavors (for me) are too harsh at 24mg. As you can see from all the great advice everyone is different....and there is no shame in having that occasional ciggy if that is what you need to keep from going NUTS

There are quite a few here at ECF that still smoke, but they smoke alot less.....as the saying goes....every cig avoided is a good cig....so if you still have one a day....well you succeeded a NOT having those other 4....that is a success in and of itself.
Best of luck and keep that chin up....you'll get there eventually
EDIT: another little trick....I have a grocery bag where I emptied my very last ashtray.....well that bag didn't make it to the trash...it found it's way into a small coffee container....just popping the top is enough to make me NOT want a ciggy....that stuff REALLY smells!!! Stale and RANK!