Agree with @scrapsoftobacco that certain activities become associated with smoking. These are what I would call obligatory smokes:
First thing in the morning
After meals or with coffee/tea
Before bed
For most individuals this is 5+ times per day. If cold turkey is not possible. then cutting back to the obligatory smokes is certainly possible. I had a roommate who tamed his demon by chain smoking 3 strong cigarettes immediately before retiring to sleep, never smoking at any other times.
Other activities, such as after sex or while drinking alcohol are, for many, not a daily occurrence. Some may need to abstain from alcohol to be successful, while sex is avoidable, especially if you are married.
The buggers are the mindless smokes (not an exhaustive list):
While driving
Talking on the phone
Online activities, especially forums, chats, or other social media
Passive entertainment like TV, DVD/Blu tay/streaming movies/video
Response to stress (perhaps one of the strongest causes of recidivism)
Awareness of & keeping track of these mindless smokes makes them easier to control & become a recovering former cigarette smoker.