Stop using the new year as an excuse to make the big resolutions in your life. You should be making resolutions (setting goals) constantly throughout the year, not just when the calendar resets to January 1st! New years is simply another day, and it’s no more or less important than the days before or after it.
This is the best resolution you could commit to, period.
That future person you want to see in the mirror one day is constantly reevaluating his life and making little changes that have the greatest impact. He isn’t sitting around at the end of November thinking to himself “well crap… the new year is only a month away, so I suppose I could just wait until then to start on the path to being happy / fit / wealthy / divorced / or whatever else!”