Most of us will make a New Year's resolution - maybe to quit smoking or lose weight - but only one in 10 of us will succeed, say researchers.
Only 25% of people succeeded in quitting smoking
But before you give up altogether, it is possible to boost your chances of success, UK psychologists report.
A year-long study of 3,000 people found men should set specific goals and women should tell the world about their resolution if they are to succeed.
And the key for everyone is not to leave the decision to New Year's Eve.
TIPS FOR SUCCESS
Men should set specific goals
Women should tell others about their resolution
Choose a new approach
Do not leave the decision to New Year's Eve
Study leader Professor Richard Wiseman, who is based at the University of Hertfordshire, found more than half of those in the study believed they would be able to stick to their resolution.
But by the end of the year, just 12% had been successful.
Giving up smoking seemed to be the hardest goal to stick to, with three-quarters of people lighting up again in the New Year.
Only 28% of people succeeded in losing weight and 29% of people who vowed to improve their fitness managed to do so.
Men were 22% more likely to succeed when they set goals for themselves, such as losing a pound a week rather than just saying they wanted to lose weight.
Telling others increased women's chance of keeping resolutions by 10%.
They benefited from family and friends encouraging them to stick to their goals.
Professor Wiseman said it was possible to increase the likelihood you will keep your resolution.
"Deciding to revisit a past resolution sets you up for frustration and disappointment.
"Choose something new, or approach an old problem in a new way.
"Think through exactly what you will do, where you will do it, and at what time."
He said those who made vague plans were more likely to fail - for example instead of planning to go running twice a week you should plan to go running at specific times every week.
He added: "Men may be more likely to adopt a macho attitude and have unrealistic expectations, and so simple goal setting helps them achieve more.
"Likewise, women might be reluctant to tell others about their resolutions, and so benefit more from the social support provided by friends and family once they have made their goals public."