We generally develop bad habits for two main reasons:
We’re stressed, and/or
Obviously there can be deeper, more traumatic issues at play, but everything from biting nails to overspending to drinking to wasting time online is most likely due to stress or boredom.
Now, stopping cold turkey is not a good plan because the behavior provides for a need. In order to break the bad habit, you need to replace it with something healthier. You can meditate or take a walk around the block. No matter what it is, you need to have a substitute already in place for the next time you get the urge to smoke or procrastinate on Facebook.
In some cases, all you need to do is change the environment, at least in the beginning. If you tend to smoke when you drink, don’t go out to bars. If you eat cookies when they’re in the house, don’t have cookies in the house. In addition to changing the environment, it’s also a lot easier to stop a habit when you’re breaking it with somebody else. By pairing up, you hold each other accountable and celebrate each other’s successes. In general, you should only hang out with people who are supportive of the new person you are becoming. There are a lot of people who like to keep you just the way you are because it serves them better.
Another technique that really helps is to walk around with a little notepad and pen, and record when you give in to your bad habit. Write down what you did and what time it happened. The purpose of this exercise is not to make you feel stupid or guilty. It’s simply to make you more aware of what’s going on with you.
Finally, when you screw up (and you will), get off your own case. There is no changing without failure. Tell yourself, “I know I screwed up, but I don’t have to screw up tomorrow.” Visualize yourself crushing it, and then go do it.