To clarify butter, melt butter in a small, heavy-bottomed pot over low heat. Remove pot from heat and let sit for 3 minutes. Skim froth with a ladle and slowly pour butter into a measuring cup, leaving milky solids in bottom of pot. Discard solids.
A good little trick is to keep the hollandaise warm in a thermos. It stays at a perfect temperature. Only hold it for 30 minutes to 1 hour and don?t reuse or reheat the sauce.