Tudor painters, such as Holbein, sometimes used a technique called "pouncing" when planning a portrait. They sketched the face of the sitter and pricked a series of holes round the edge of it. Then they laid the paper on a board and dusted it with pounce (a find powder of charcoal or similar substance). The powder went through the holes making a "join up the dots" outline which they could fill in with paint. Use one of the portraits to make a pouncing pattern.