"Bad character traits, such as anger, hatred, and jealousy (Maimonides, "Laws of Repentance" 7:3).
These almost always lead to violations of other fundamental laws. For example, hatred and jealousy make it impossible to fulfill the biblical command to "love your neighbor as yourself" (Leviticus 19:18), while a bad temper causes one to say hurtful things.
A Code of Jewish Ethics: Volume 1: You Shall Be Holy, Rabbi Joseph Telushkini
1. "Since, as we explained, man was granted the capacity to do so, he should strive to do teshuvah, verbally confess his sins and reject them all, so that he might die having done teshuvah and merit life in the World to Come.
2. A person should always consider himself to be on the brink of death, and realize that if he were to die at that moment he would still be guilty of sins. So he should consequently do teshuvah immediately rather than say “I’ll do teshuvah when I get older”for he might die before then. That’s what Solomon meant when he said in his wisdom, "Let your clothing always be white" (Ecclesiastes 9:8).
3. Don’t think that one should do teshuvah for transgressions that involve[concrete] actions like promiscuity, robbery, or theft, alone. For just as a person has to do teshuvah for them, he also has to determine his bad traits and do teshuvah for those like anger, hostility, envy, sarcasm, the pursuit of wealth or glory, excessive eating, etc.,because these, too, require teshuvah. For those sins are even more serious than the ones involving [concrete] actions.Because when a person is steeped in them, it’s very difficult for him to relinquish them. As it is said, "Let a wrongdoer abandon his ways, a transgressor his thoughts" (Isaiah 55:7) ."
Maimonides, "Laws of Repentance" 7:1-3
Suspecting the innocent. As long as we do not voice our suspicions publicly we have not harmed anyone right? Did you ever lose something around the house and just could not find it? Did you start thinking about visitors to your house or maybe that the cleaning lady misplacing the item or taking it? Voicing these thoughts between yourselves is not a violation is it?
Maimonides disagrees as we can read below.
4." Included in this category are five things which one is not likely to do teshuvah for since they’re seen as being of minor importance, and because it appears to the guilty person that he wasn’t sinning. They are: a) partaking of a meal that’s barely enough for the person offering it which is a type of theft, and thinking that’s not a sin, assuming he "ate with his host’s permission", b) making use of a poor man's collateral, even if it’s only [something common and inexpensive like] a hatchet or a plow, and saying: "He won't miss it. And it's not like I'm stealing it", c) staring pruriently at nudity, thinking doing that isn’t serious and saying to oneself, "But have I had intercourse with her, or even drawn close to her?", not knowing that staring is itself a serious transgression because it fosters actual promiscuity. As it’s written: "Do not follow after your own heart or eyes" (Numbers 15:39), d) using another's personal failings to one's own advantage, and thinking that that is not a sin because the person is not actually there at the time to be embarrassed or ashamed, and because the guilty person is only comparing his own good deeds or wisdom to the other's in order to let it be known that while he himself is praiseworthy, his victim is shameful, e) casting aspersions upon people with good reputations, not considering that a sin and reasoning, "But, what have I done? I've only aroused a suspicion He might have done it or he might not", for one who does that does not realize that suspecting a person with a good reputation of being a sinner is itself a sin."
Maimonides, "Laws of Repentance" 4:4
Elements of Repentance
In this video, Rabbi Fohrman introduces and begins to analyze Maimonides’ 4 elements of repentance, and suggests that the last of the 4 seems not to fit with the first 3. The first 3 elements highlight the process of leaving behind a sin. Rabbi Fohrman points out that merely leaving sin behind does not accomplish real repentance; that’s where confession comes in.