Use RIT dye in the powder or liquid form successfully every time. Other brands of powder and liquid dye will work if used correctly, but we found that RIT consistently delivered high quality color.
You need a container in which to dye the head. Use a container that is large enough and durable enough to withstand the heat of boiling water. An old kitchen pot that the family is no longer using or silver paint containers that are deep enough to fit a stick into are good. We recently discovered that using an aluminum turkey cooking tray from your local grocery store works the best. The turkey tray should also only cost you a couple of dollars, and it makes for an easy disposable cleanup.
If you are planning on creating some kind of design and are dyeing your head something other than one solid color you will need some of the following.