I often take a reading off my palm (zone VI) with my Digisix - but: much depends on what light is falling on your palm. By turning the hand slightly you can easily get a two stop metering difference, and that's where experience takes over. Try and test again and again and you'll end up knowing how to meter the light.
I personally find that metering thelight for an exposure is the most difficult part of producing a good print.
Peter