[slickster81]

Low to medium low heat and patience. What you are doing actually has 3 phases.

1 - Butterfat melts and water evaporates out of the butter.
2 - Milk solids separate from the butterfat.
3 - Milk solids begin to brown in the butterfat (and the fat browns as well).

I usually start out with a medium heat, once the butter melts it will foam, when the foaming subsides, the water is gone.
Lower the heat a bit and stir well, scrape the crust off the sides into the butter.
WATCH it closely, the bits in the bottom will begin to brown, when they do, watch even closer as they will go from a nice golden brown to coffee grounds black in no time. When they are a medium brown, take the pan off the heat and use the butter.

Browning butter properly takes about 10-15 minutes once you get the hang of it.

The brown butter/sage recipe is more forgiving if you add the sliced garlic as the garlic will be nice and brown before the butter can burn. Plus it is just plain yummy!