Try to think of something positive. Something that you're actually going to get from not smoking. I know that, you know, not-dying is a pretty good thing to get out of it, but what you should do is divert the smoking resource to something else. Something big. Like a car, or a new stereo, or whatever you want.
The trick is that if you are smoking a pack a day, and a pack costs $5, then every day you put $5 in a jar. This jar will fund whatever you're saving for.
Then, when you get to the money required to buy the thing you're saving for, you will have actually achieved something, and made all the cravings, and suffering worthwhile.
And the other thing is that every day you can count your money, and feel proud that you've saved it, by taking this decision.
I don't want to sound flippant, but what I'm trying to say is that you should make the health benefits secondary in your head, because now, when you're young, you don't feel the damage you're doing, and so there's no reward for not doing the damage.
It all comes back to reward, actually. You have to come up with something that's more rewarding than the smoking itself.
Good luck.
