From the very beginning you have to show great love and understanding. If punishment is ever needed you have to do it to help the child grow and not in a fit of anger. The punishment must fit the crime. You must never threaten..if you say you are going to take away, say her doll then you have to take away her doll. Never fight with your spouse around her. Never disagree about her against your spouse in front of her. Give her the benefit of a doubt.
If you allow your friends to spill their drinks and treat them with kindness, don't turn around and scold her harshly for doing the same thing.
Love and understanding is most important. Respect her in order to get respect from her. Treat her the way you want to be treated.