Give time. No one wants to be ignored just for some meeting or work. Give time to each and every one of them so you can understand every individual properly and this can prevent any misunderstandings in the future.
Treat everyone as equal. Whether its your maid or step child, they also deserve love and affection from you as you deserve from your wife/husband or from your own child. Treat everyone like you would want to be treated, and getting along with your family should be easy