Limit yourself: One of the biggest pitfalls of New Year's resolutions is the sheer number of them we tend to make. According to DeVore, it's unrealistic to think you can work toward achieving more than one major goal at a time. Creating a long list of life changes you want to make is going to be an exercise in frustration. Even if you do manage to achieve a couple of the goals on the list, you'll feel like a failure for not being able to achieve the rest.

Make SMARTer resolutions: When you are setting a goal for yourself, analyze it based on the "SMART" criteria: S-specific. M-measurable. A-attainable. R-realistic. T-timely. If your goal doesn't meet all of those criteria, you should reassess what you're trying to accomplish.

Don't set yourself up for failure: "People have a tendency to think about things in an all-or-nothing way," says DeVore. And that sort of black-and-white thinking can actually stand in the way of what you're trying to achieve. So, if your goal is to lose weight, DeVore suggests focusing your efforts on eating more healthfully, rather than locking yourself into an unrealistically restrictive diet. "Keep things flexible," he says.

Reward yourself: Just as important as coming up with a realistic, achievable goal is deciding what rewards you'll build into your program. It's great to have your eye on a big reward that you promise to give yourself if you achieve your goal, but it's also important to allow yourself smaller rewards for successes along the way. For example, if you're trying to quit smoking, take the money you would have spent on cigarettes every day and use it to buy yourself an end-of-week treat.

Bite off manageable pieces: Don't get overwhelmed -- and ultimately disappointed -- by trying to take on a goal that's too big. Your goal may be to start an exercise program, but if you tell yourself you have to do an hourlong workout every day of the week, chances are good that you will fail to reach that goal most weeks. Instead, start small -- set your sights on getting at least 20 minutes of exercise most days of the week. And once that seems too easy, up the ante and schedule in longer sessions. And remember, even getting just a little exercise is still a big step toward your ultimate goal of making exercise a regular part of your lifestyle.

Don't let missteps derail you: The key to keeping your resolutions and achieving your goals is to stick with them -- even when things aren't going well. "You have to be careful not to tell yourself, Oh, I messed up, so I might as well give up," says DeVore. He suggests making a "benefit card" when you set your goal. On it, write down all the benefits you will reap from achieving your goal. Whenever you slip up, go back to the card to remind yourself of all the important reasons you want to get back on track.