Melt the butter over medium heat (7 out of 14 on my stove). Avoid stirring it. As the butter melts, the whey will settle at the bottom.
Turn up the heat when the butter has melted (11 out of 14 on my stove).
Stir it every other minute. It should come to a boil to develop the good nutty flavor and aroma, but the temperature should not be too high - this will give a burnt taste to your browned butter.
Let the browned butter run through a cheesecloth or a cloth diaper - optionally into a mason jar if it is to be saved for later, or into a bowl.