I experimented with a sphere trying to incorporate some of the things I've learned.

I did my best to flatten the shadows.

I have problems with the halftones, keeping them clean and obtaining different halftones. They usually get muddy.

I see in this case I could have turned the form more near the terminator, but I worried I'd get too close to the reflected light tone.

I was unable to shade in small patches and follow the form, I ended up using more circular and around the form moves.

Mark, please share your thoughts!