The
GW way is somewhat like this....
Prime black.
Base of Dark Angel Green.
Go over 90% of the model with Goblin Green leaving the recesses of the flesh Dark Angel. This is pretty time consuming and if you are painting a bunch of dudes, it can be maddening. Make sure you are comfy and whatnot.
Pick out those highlights with a 50/50 mix of Goblin Green and Bleached Boner (Ouch! haha)
Then wash with a Dark Angel Green. You'll have to thin down the paint here to a viscosity somewhere between milk and water. Apply it evenly and don't let it bubble or pool excessively in recesses. Use an alternative brush as a sponge to soak it up where you think it might be too thick.
When the wash is dry, go back over the extreme highlights with a good small scale brush (a 10/0 or anything with a really fine point is good...I should mention here that
GW brushes aren't that great and that you can buy superior brushes for a fraction of the cost at almost any craft or art supply shop just in case you didn't know...just tryin to save you some dough for more minis here) with a mix of goblin green and Bleached boner. You can go heavy or light on the bleached bone here, but use it sparingly and at the true high highlights.
This is how I do Ork/Orc skin and I have done it like a bazillion times. I've won a few painting comps with my boyz, so the effect is pretty close to the
GW way esthetically. Hope this helps.
The picture is total gak (someday I will put a better one up I promise) but you can see what I mean....hopefully
http://www.dakkadakka.com/dakkaforum/posts/list/268703.page#1167079