Working on another part today that requires a gorgeous finish, this time as a showpiece in aluminum, so the dimensional accuracy isn't as critical.
The part has features on five sides, and all the finishes need to flow perfectly from one to another. It took me a while to understand how to program it after my boss explained, due to the unique shape that couldn't be held on the end that well. The basic idea on how to do it is to mill out the first side in a piece of bar stock, cutting each about half the depth of the part, leaving a small square block toward the bottom that you would use to reference off of when holding it upright. Since I would be holding it in steel hard-jaws, I couldn't cut it out, so I would have to cut it most of the way, then flip it over and remove the back material.
On that same first operation, you would finish that side but leave stock on each of the walls to clean up on the final op. The area I took longest getting my head around was holding the part upright in the vice. On the front face of the piece has a dome shape and I thought it would get ruined by the clamping force of the soft-jaws; what I didn't take into account was how little pressure would be applied from each of the milling operations and so wouldn't require as much to hold them in place.
Using the square base of the part from the first operation, you can set the work zero at the same corner and set each tool off the top face, giving you the same reference when rotating it 90 degrees.
I was able to finish up the first operation and programmed most of the rest of the part before I left. I'm not entirely pleased with the surface finish as it left a square-shaped mark where the bed of the minimill moved at a sharp angle instead of flowing from the center (see image)