Finish is everything. If the finish is not good it can ruin the whole project. Many times it takes as long to finish a project as it does to turn it.
I generally sand as much as I can while the project is on the lathe and then hand sand the finishing touches.
Inlayng TURQUOISE and COPPER in the natural cracks and voids is the last thing I do before putting the final sanding touches on.
For my finish I use General Finishes ARM-R-SEAL clear and ARM-R-SEAL gloss topcoat. I use a foam brush to apply several coats of the sealer but spray the final coats on. This gives it a real smooth looking finish and brings out the natural look of the wood. It also highlights the decorative materials that I use. I have always liked the gloss finish the best.