Alrighty, it's time for some:
There's not a great deal of add-on details on R2D2's dome. There's an eye in a little square-ish mount, three holographic projectors, and a bunch of painted-on details.
The eye surround was cut from the Christmas bauble that I had determined in the early stages was far too large to use for the dome proper. As the eye frame is essentially a chunk cut from a dome of a larger diameter, the Christmas ball turned out to be perfect. The little lip at the bottom, and the structure underneath to give it some height were all cut out of styrene offcuts and attached with cyanoacrylate. I don't have a photograph, but the hole for the eye lens was made with a drill.
The holographic projectors.
"Help me, Obi-wan Kenobi. You're my only hope."
R2D2 has three holographic projectors that protrude from his dome. They're all pretty much identical, and consist of a tubular lens extending from a sphere that allows the projectors to point in various directions. I had no intention of replicating the directional ability, but the basic shapes were essential.
After a few experiments with various beads and baubles, I stumbled upon.....push pins.
By cutting the flat end off, and drilling out the stem, the push pins resemble the holographic projectors pretty well! After drowning them with primer, they got chromed and put aside to be attached to the dome after the panels get painted.
Up next: Painting the barrel and legs!