Don't try to do it all on your own. Tell someone about what you're doing.
Someone who smokes may want to simply put the pack down and call it quits, but for instance, if you smoke 10 cigarettes a day, cutting back to nine and so on until you gradually quit might give you the best chance of sticking with your decision.
A lot of what goes into making positive behavioral changes has to do with mental preparation. If you want to achieve that New Year's resolution or any other goal, you have to start out by setting some small, but realistic goals.
Instead of completely swearing off your credit cards, start off by having a small amount deducted from your pay and transferred into a savings account.
