Everyone makes mistakes.

No one is ever perfect in life, everyone has some or other flaws. It’s okay to make mistakes, but it’s essential to accept them and to make sure that you don’t repeat the mistake ever. A person could make a minor or a major mistake, but if anyone wants to change themselves, then always give them a second chance to prove themselves.

If a person has made a mistake but is not aware of it then, first talk it out to them. If they still do not accept their mistake, DO NOT shout/scold at them, but instead take a polite measure. Do things to them that they do not like. For example, if he/she does not like it if a person is too kind to them, then be kind to them. Or don’t talk to them at all i.e give them silent treatment. But never speak harshly to someone, and always hear out everyone's side of the story as the person might have taken actions for some reason.

If a person is doing something repeatedly that is troubling you, then try to make them realize that their actions affect you (It could be some wrong habit of theirs or irritating behaviour). But do not fight it out as it might make things worse.

Once they accept their mistakes and realize that they have hurt your feelings, try to explain what they should have done instead and forgive them.