My problem? I was not using a large enough brush. There was no real center of the brush for paint to get into so that when I brushed it across the figure, nothing was actually being applied. I am sure there is a proper way to do it with a 10/0 brush, but reverting to a 3/0 brush did wonders for me. I think I have finally had some success with my first Ork.
Most of the paint on him is just the foundation paint, with no washes or other colors applied over it, but all of his green areas were given Orkhide Shade for foundation, then washed with Thraka Green, and then drybrushed with Snot Green. The side view shows it best on his arm, as you can see the contrast. Still not perfect I am sure, but it feels good to know that you are on the right track in doing something, so that you know you will improve further in time.
For the curious, he will not stay so overwhelmingly leathery brown, I am just using the Calthan Brown as a base. The leather straps will actually get a reddish tinge or just go more towards red entirely, and his gloves/boots will be a bit tanner with Snakebite Leather. He is my test ork, and his color scheme will be duplicated across the Boyz. More to come later.