Use unsalted butter (salted butter can be used, but adjust later)
Cut butter into small pieces for even browning
Choose a light-colored skillet or saucepan to see the color change
Melt butter over medium heat
Stir occasionally (or swirl) to prevent scorching
Watch for foaming and then browning flecks at the bottom
Remove from heat when it turns golden brown and smells nutty
Strain if you want a smoother result
Use immediately, or pour into a heat-safe container to stop cooking
If it browns too far, start over (it can turn bitter quickly)