Tips from Lifehack.org

1. Replace Lost Needs. Most habits fulfill a purpose of some kind, even if the side-effects are negative. You might watch television to relax, even if you have other things you would rather do. You might eat junk food to feel full, even if it isn’t healthy. Consider what you are giving up in your habit change and make an effort to replace those lost needs.
2. Write It in Ink. A commitment inside your head isn’t a commitment at all. Keep a binder where you can store written commitments for habit changes. Not only will writing reinforce a promise to yourself, it will clarify your thinking as to what exactly you want to change.
3. Commit for a Month. Resolve to stick to your change for at least thirty days. Less than this and you are likely to fall back into old habits. Three to four weeks is all it takes to condition a new habit.
4. Keep a Journal. Open up a new word document and commit to writing a few sentences each day about your progress. I’ve found this method helpful in reminding me about my commitment and helping me focus on the change I want to make.
5. Strategic Enjoyment. One way to create more positive feedback is to structure your habit so it becomes more fun. Going to the gym isn’t the only way to exercise if you hate it. Eating tofu isn’t the only meal option for vegetarians. Look for ways you can make a new habit more enjoyable.
6. Think Years, Not Months. A diet that consists of grapefruit and water isn’t going to provide nutritional needs to last your whole life. Work on creating changes to your diet, work, exercise or routines that can be sustained for years. Crash diets and 18-hour workdays will eventually break.
7. If You Slip Up, Start Over. I consider a habit change complete when I can go thirty consecutive days. If you slip up and break your habit on the 3rd, 15th, or 27th day, start over. This keeps you from cheating on days with the excuse that you will resume the day afterwards.
8. Behavior First, Results Later. Don’t let watching the scale or your bank account discourage you when trying to change a habit. The correct change in behavior has to come before any results start to appear. Focusing too much on losing weight, working less or being rich and throw off your attempts to form good habits.
9. One Habit at a Time. Don’t tackle several changes at once. Successfully conditioning one habit change is more useful than giving up on a half dozen changes after a month.
10. Learn From Mistakes. This one is pretty obvious, but it’s surprising how many people when they fail to make a change, go back to using the exact same strategy. Figure out why you failed previously, and don’t be too quick to blame willpower.
11. Consistency Counts. A habit that is performed the same way, at the same time and under the same conditions every day for a month will be reinforced far more strongly than one that changes throughout the week. Be consistent and you can spend less time reinforcing a habit.