Your aunt gave you bad advice. Whenever you get drawn into arguing, you are letting the other person control you. Being independent means you make your own plans and you don't have to explain or defend yourself. Arguing with your mom is basically you pleading with her to accept you in the way you'ld like her to. Don't plead. If she's the argumentive type, let her do the talking and just don't respond. Be polite, but don't get verbally jerked around. Sometimes, the most effective way to project personal power is to simply stay calm and quiet.