The most helpful thing to do from a learning and career standpoint is to learn to see, mix, and understand flesh tones yourself.
Like the Flesh crayon in the box of Crayolas, premixed flesh tones are rarely going to match those of your subject. Humans have several differing tones of skin (yellow, orange, red, olive). Further, light plays over the skin and changes and tints its hues.
Learn to see skin and mix tones that match for each portrait you do. There are many books out there that can help you get the basics of flesh tones down. Look also in this forum for some advice.
Hope that helps!
