The first week you will feel awful. The toxins that had been accumulated in your body now want to get out and you may feel sick, coughing out some green slime. Also, your lungs get some extra space to breathe and you may feel a bit dizzy from the extra oxygen. All this can discourage you.
1. Remind yourself that if you have a cig now, you'll have to go through all this again in a while. You still need the effort to bypass the initial disgust with the first cigarette, so it's actually difficult to start smoking again.
2. Don't go out much. Avoid the people who can tempt you into smoking.
3. Avoid alcohol and coffee. If you are used to smoking with beer or coffee, just don't do it the first week.
4. Use some other form of satisfaction instead. To fulfill the hole you can try and make it up with some other activity, eat something new, drink some expensive vine, try something new in your bedroom.
5. Use your regained lung capacity to start exercising more. A day in a gym will show you a preview of what you can gain if you stay clean. And the hormones which are pumped while working out will make you wish you never started smoking.
6. Plan your every moment for the week to come. The tactics they use in the army is "The working soldier will not think". If you don't have the time to think about it, it's less likely you'll get tempted to smoke.
7. Find yourself a reward at the end of the week, but not a cigarette.