The reason I think making commitments to change one's deeds is a good things is this. It is based on something I learning with my telescope looking at the stars. I noticed that if u look directly that it gets out of focus. But if you look slightly to the side then the star is clear. Thus I see the idea of making commitments as a way of solving personal problems. That is: I see there are lots of problems in my life that I cannot solve. And I also see if I take the direct approach that usually backfires, or at least does nothing to solve the problem. Therefore I say like Rabbainu Yona in the Musar Book Shaari Teshuva that אין יסורים בלי עוון "there are no problems without sin." So it must be that the problems are coming from something that I am doing that I ought not to do, or from lack of doing something that I ought to do.

The study of Musar {Mediaeval Ethics} has helped me understand certain areas of improvement that I have needed to face. But as a general rule it is certain that Reb Israel Salanter would have said that if you are going to make any commitment to do anything it should be to learn Musar every day  for a certain length of time.
I have a lot of faith in this idea of Reb Israel Salanter and my older brother agreed with me when I mentioned it to him. Still I do not want to put too much into it. We do not want a scenario in which people are learning Musar and acting badly --  which would discredit the whole idea. Rather Musar is a simply a way of recognizing your own personal faults and working on them if you want to. It is no guarantee to have or to acquire  good character.  

It is a map but it is not the destination.

In any case commitments can not be things you pick out of a hat. They have to be things you anyway believe to your best knowledge that these are God's Will for you, but you just have not had the will power to do them.