Baking recipes often call for softened butter, but if you put the butter in the microwave you risk butter soup. Leaving it out at room temp is fine if you've got lots of time. But when your butter is cold and hard and you want it to be warm and soft, just pound it with a rolling pin.
How to Brown Butter
It imparts a nice nutty flavor to food.
Salt from on High
The higher your hand, the more even the distribution.