How does one avoid the dangers of self- exoneration?

The self commands man to do evil. This fact is related in Surat ash-Shams as follows:

By the soul and the One Who proportioned and inspired it with knowledge of depravity and with its sense of duty, he who purifies it has succeeded, he who covers it up has failed. (Surat ash-Shams, 7-9)

Another verse pointing out the capacity of the soul to command to do evil is about the Prophet Yusuf (peace be upon him), It is told in the verse that when a lie was forged against him though he was innocent, he said:

I do not say my self was free from blame. The self indeed commands to evil acts—except for those my Lord has mercy on. My Lord, He is Forgiving, Merciful. (Surah Yusuf, 53)

As it is told in the verse, the self always commands to evil. For that reason it would not be appropriate to try to defend oneself or to prove one’s rightness immediately, for one might have momentarily and unawares followed what the self desired. What should indeed be done in such a case is to stop and reflect first before acting. When a person reflects sincerely and honestly, he may see that he in fact did wrong in many instances in which he assumed himself to be right. Perceiving things in this way is an enormous gain to the believer, because seeing and admitting one’s own mistakes and amending one’s wrongdoing is the first step in seeking the forgiveness of Allah. Otherwise, no matter how right a person may appear to be in the eyes of people, however hard he tries to vindicate his soul and avoids attributing any mistakes to himself, Allah knows the truth. And this truth he will meet in the Hereafter. It is a good action in the sight of Allah to reproach oneself, to admit one’s own imperfections and failings and to turn to Allah in order to eliminate them, rather than to defend one’s lower self.

How does one avoid the dangers of self- exoneration?