Hello Macroslut, welcome to the forms. There is a current thread on how to punish a masochist.
http://www.bdsmlibrary.com/forums/showthread.php?t=6222
However I think your looking to make your submissive feel the pain of smoking when she agreed to obey your order not to. I have some experience with this particular activity. What I learned was that you will need to have complete control over her for a period of about 2 weeks, until her system is completely free of the toxic requirement of nicotine. If you are not able to maintain that, she may very well sneak a smoke in. The need for a smoke can be that overwhelming.
To the point of your question about making the punishment fit the crime. Smoking usually makes it hard for a person to breathe. Once they quit smoking they find they are able to breathe easier during times of increased physical activity, such as running for example.
If your submissive is in relatively good health, you could start a mild exercise program for her. Smoking would induce its own punishment, since when not smoking she would be able to do the exercises with fairly little trouble, and when she does smoke, it would be that much more difficult to complete the very same exercise routine.
The pain she needs to feel as punishment must not be one that induces pleasure, as the paddle or whip can do for someone who enjoys pain. Not too many people enjoy the crushing effect of not being able to breathe when it is not part of a play scene.
Therefore the effects of smoking should be felt when she is smoking, and would not be effected by them when she is not smoking.
I hope this helps.
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