3. Be kind.
In contrast to the Wicked Witches, Dorothy is always kind to everyone she meets along the Yellow Brick Road. While Dorothy gets to go home, the Witch sisters end up flattened by a house and reduced to a molten puddle of slime.
4. You have the power.
Dorothy learns this powerful lesson when Glinda reveals that her totemic obsession with the ruby slippers was a red herring and, really, she always had the power to go home.