To get free milk, go to south termina and go under the log. Put a bomb in the center to make a hole, then go in it. There will be cows, then play epona's song. They will give you milk. You can do this as much times as you like to get all the milk you want. There is also a funny thing about this. When they are saying that they like the song and it reminds them of the pasture, they will laugh like a girl.