There are commentators who explain that this new commitment for the new year is like a new garment that a person buys - a garment not for the body, but for the soul.
The commitment needs to be modest, doable, and within reach.
Rav Elimelech Biederman tells the story of a student who approached his rabbi at the beginning of the year and asked for a worthwhile commitment to take upon himself. The rabbi answered: think about, contemplate, and then choose an easy commitment that you are certain you can live up to throughout the year. The student returned to the rabbi with a promise to undertake a certain commitment.
The rabbi then told him: now cut that commitment in half in order that you will be certain to fulfill it.
Wishing everyone a good year with good commitments.
* Translation by Yehoshua Siskin