Here are University of Hertfordshire Professor Richard Wiseman's tips for successful New Year's resolutions.

• Make only one resolution: Many people make the mistake of trying to achieve too much. The chances of success are greater when people channel their energy into changing just one aspect of their behaviour at a time.
• Plan ahead: Do not wait until New Year's Eve to think about your resolution. Last-minute decisions tend to be based on what is on your mind at that time. Instead, take some time out a few days before and reflect upon what you really want to achieve.
• Avoid previous resolutions: Deciding to re-visit a past resolution sets you up for frustration and disappointment. Choose something new, or approach an old problem in a new way. For example, instead of trying to lose two stone in weight, try exercising more.
• Be specific: Think through exactly what you are going to do, where you are going to do it, and at what time. Vague plans fail. For example, instead of saying that you will go running two days of the week, tell yourself that you will run on Tuesdays and Thursdays at 6pm.
• Set S.M.A.R.T goals: Focus on creating goals that are Specific, Measurable, Achievable, Realistic and Time-based (smart). For example, instead of thinking "I want to find a new job", focus on creating bite-sized, measurable goals for each week, such as rewriting your CV and then applying for one new job every two weeks. Map out the step-by-step mini-goals that will slowly take you to where you want to be, make a note of them in a diary, and stick to the plan.
• Carrot not stick: Focus on how much better life will be for you, and those around you, when you achieve your resolution. For example, if you want to quit smoking, make a list of the benefits of giving up, and place it somewhere prominent in your house. If you want to motivate yourself to go to the gym, find a photograph of a fitness model that appeals to you, and put it in a place that ensures you will see it each day.
• Go public: Many people keep their New Year's resolution to themselves. But this makes it all too easy to forget about them. Instead, go public. Write down your resolution on a large sheet of paper, sign it, and place it somewhere prominent in your house. Tell your friends, family and colleagues about your resolution, and ask them to provide you with helpful nudges to assist you in achieving your goal. Either way, do not keep your resolution to yourself.
• Be persistent: New habits take time to learn, and once in a while you will slip up and revert to the old you. People on diets might suddenly give in to temptation, or those trying to exercise more might not find the time to go to the gym for a week. Remember that everyone messes up from time to time. Don't blame yourself if you falter, or allow the experience to make you give up.
• Visualise yourself doing whatever it takes to achieve your resolution as this will help you believe you can do it and see it through.

Be positive: It is better to think about the good things that will flow from a healthier lifestyle than the bad things that will result from an unhealthy one