Remove existing coatings (for thick coatings, use a 16- or 20-grit diamond abrasive or more aggressive tool specifically for coating removal, such as a T-RexTM).
Seal cracks and joints with an epoxy or other semi-rigid filler.
Grind with a 30- or 40-grit metal-bonded diamond.
Grind with an 50-grit metal-bonded diamond.
Grind with a 100-grit metal-bonded diamond (or finer, if desired).
Grind with a 200-grit metal-bonded diamond.
Apply a chemical hardener to densify the concrete.
Polish with a 100- or 200-grit resin-bond diamond, or a combination of the two.
Polish with a 400-grit resin-bond diamond.
Polish with an 800-grit resin-bond diamond.
Finish with a 1500- or 3000-grit resin-bond diamond (depending on the desired sheen level).
Optional: Apply a stain guard to help protect the polished surface and make it easier to maintain.