Man the butter timing is everything. I wrecked probably a dozen pans before a buddy finally told me to pull the pan off the heat for a solid 20-30 seconds before swirling the butter in. Now I do butter last, off the flame, and I swirl until it just melts and emulsifies. Also found out the hard way that cold butter straight from the fridge splatters and breaks way worse than if you cube it up small and let it sit out for five minutes first. That little extra patience made my sauces go from greasy mess to restaurant level.