Drink lots of water to flush your system, and give you something other than your usual beverage to drink in order to break your habit patterns. Take a different sort of break that doesn't involve hanging with your smoking buddies. Maybe even give up coffee or tea for a couple of weeks if you drink those things while smoking. Go for a walk when you get antsy. You will get really "windy" as your body adjusts to life without nicotine drugging your body (which includes the lower intestine). That wind will pass after a few days. Shower a lot and enjoy feeling fresh. Find some mindless time consuming task that needs doing and do it. You need to put a couple of weeks behind you in order to get through the initial stress on your body as it tells you over and over that it is ready for another cigarette. Remember, every smoke you've had is a conscious choice. Simply choose to not have a cigarette. You will notice that the majority of the cigarettes you have are due to a habit, not a need. I found myself making that no-cigarette choice about once every 5 minutes sometimes
Good luck, and don't feel like getting careless/casual and having one cigarette is the end of the world. It is just a cigarette. The key is to increase the time between smokes. I have gone for years on end. The last one I had recently was 6-7 months ago. No big deal.