I don't smoke but I have family members and friends who do. Another friend runs a Christian Drug Recovery Home called "In His Steps". In my experience watching others, there are three main things that draw people back to smoking. #1: The addiction of the nicotine and the inability to get over it. Using the gums, patches, and the electronic cigarettes keep you addicted to the nicotine and at some point, you'll probably go back to smoking. If you can avoid these products and go cold turkey, do it. #2: The void of smoking is not replaced with something else. If your mind is only focused on not smoking, don't kid yourself, you're still thinking of nothing but smoking. Find something to replace it with that is healthy. Use the money you save by not smoking for a reward (something you really want) and set a realistic goal (# of days not smoking) to buy what you want. Try a sport, exercise, or activity to keep your mind off of smoking. If you are busy, you won't have time to think about smoking. #3: The habit or muscle memory involved with smoking. If you've been smoking for a long time, you will feel a bit of a void when not holding a cigarette. Replace the cigarettes with something else until you no longer feel this void. I've seen many past smokers take up eating baby carrots because they are similar in size to cigarettes and go in their mouths. This deals with the muscle memory and replaces a bad habit with a good one.
Once you're free of the addiction, have filled the void, and have gotten rid of the habit, you should be in the clear.
Good luck and keep at it.