The hair should be at least 1/4-inch to 1/2-inch for best results. If you have coarse hair it should be closer to 1/2-inch for the first few waxes. Once the hair becomes finer it can be waxed at a shorter length. If your hair is longer, I recommend shaving the area and booking your waxing appointment for two to three weeks later.
It may take up to three waxing treatments to achieve smooth skin due to the fact that hair grows in stages and all of your hair is never at the same stage. It is very important to avoid shaving between waxing appointments, as this will interrupt the process and stimulate the hair growth again.