You see in Musar [books on ethics] an emphasis on correction of character traits. The reason I think is this. One might be aware of his own sins and try to correct them. But that leaves the root of the sin not fixed --the kind of fault that led to the sin. And also sins can be hard to identify, and sometimes even if one is aware of them, they might contradict each other. That is the very nature of the spirituality--It does not lend itself well being reasoned about. Thus it is best to work on one's character and by that uproot the source of ones faults.
I have tried to identify my sins by mean of experience. That is: to see what actions caused problems. This is often easy because one can see immediate results. Other times the results of certain actions can be a long time coming. But in any case, this is better than reasoning from books, for the mind is often highly misleading. One can find anything he wants in any books. This is unreliable.
