More than half of all resolutions fail, but this year, that doesn't have to be you. Create a plan on how to reach it, and become part of the small group of people that successfully achieve their goal.
Pick the right resolution: Give yourself the best shot at success if you set a goal that's doable and meaningful too. The reasons why resolutions fail is because it was created based on what someone else or society is telling you to change or you don't have a realistic plan for achieving your resolution. Your goal should be smart and a clear concrete goal. Don't try to take too big of a step too fast which can leave you frustrated. The goal should matter to you. Don't do it out of the sense of self hate or remorse. If you build up a process where you're thinking harder about what's good for you, you're changeing the structure of your life and bringing people into your life who will reinforce that resolution, then I think you have a fighting chance.
Allow yourself enough time to do it with lots of smaller intermediate goals set up along the way. Focus on these small wins so you make gradual progress. If you are building a habit, you're planning for the next decade, not the next couple of months.