How many times a day do we think about things that are negative like "This world is so awful." or " My sister never treats me right." ? These kinds of thoughts will keep us in unrest and we must put them aside. We must replace them with peace making thoughts instead. Think about how beautiful the world is and that we are all here to love one another and be good stewards. Love your sister even though she is acting badly. Think of all of her good traits.
This kind of thinking puts you in a good place and sends loving, peaceful energy out into the space around you. This energy is felt not only by you but by everyone in your presence.