It is recommended to take on a kabbalah, an exact plan for improvement. It doesn't have to be a big undertaking, and in fact, it is better when the kabbalah is a relatively small and easy thing to do because then there is a greater probability that it will be kept throughout the year.
It states, אלקיך 'ה עד ישראל שובה, "Do teshuvah up to Hashem, your G-d." Rebbe Shmelke of Nikelsburg zt'l explains, ישראל שובה, do teshuvah, עד, up to a certain point. Don't take on too much at once because you will fall from your resolve.
The Beis Avraham zt'l told the following mashal: An alcoholic resolved never to drink alcohol again. He made this kabbalah at night, and true to his word, he didn't have his usual late-night drink. In the morning, he craved a beer and began walking toward the put, but he stopped midway. "I can't do this," he told himself. "I'm a new person. I'm not an alcoholic anymore," and returned home. In the afternoon, he walked all the way to the bar but caught himself in time and returned home. By nighttime, he complimented himself. He said, "Today, I controlled myself all day. I had four or five difficult tests, but I was strong like iron and kept my resolve. For this, I deserve a reward," and he went to the bar to celebrate.
Often, our teshuvah looks the same. We resolve to improve in some area, are successful sometimes, and then we pat ourselves on the shoulder, drop our guard, and promptly revert to our old ways. Instead, we need to make a firm decision, once and for all, and then we will succeed with our teshuvah.
