Use two mirrors : Coloring the back of your head can be tricky. As you apply dye in front of your bathroom mirror, hold up a handheld one to ensure you don't miss spots, Hill recommends. Have cleansing cloths on hand : Use wipes like Neutrogena Makeup Remover Cleansing Towelettes to soak up any dye splatters as they happen. If you wait until you're done, they may have already set. ("I still have stains I can't get off!" one tester sighed.)
The last thing you want is to run out of dye halfway through the process. If your hair is shoulder length or longer, you may need two boxes to cover your whole head, depending on hair thickness. (And if you end up with a leftover box, you can always use it next time) Take the strand test : If you're trying a new shade, test it on a few trimmed hairs or hidden pieces first, and look at the result before you commit. A common horror story from testers who didn't do this: hair that turned orange and purple!