Three tries is the charm! I first made the grisaille and had to really work against the impulse to blend in every brush stroke. But in the end I was pleased with the result of the cups, even if the shadows and background needed some work.
Then I started in on the color. Of course, I haven't painted for a week, so it was like trying to exercise after a vacation of laying around. I was surprised how out of practice my mind was. It turned out really flat and I couldn't get the background right. So I let it dry and painted over it.
I still have to work on the consistency of paint. I used much wetter paint for this and I think still a bit too much medium (hence the shiny brush strokes in the picture). But I'm getting better. I also had trouble making the color vibrant enough. The color of the actual cups seems more vibrant, but I couldn't get the right mix. All in all though, very pleased with the result.