How can I effectively use a double boiler for melting chocolate?

To effectively use a double boiler for melting chocolate, fill the bottom pot with water and bring it to a simmer. Place the top pot with the chocolate on top of the bottom pot, making sure it doesn't touch the water. Stir the chocolate occasionally until it melts evenly and smoothly. Be careful not to let any water or steam get into the chocolate, as it can cause it to seize.