What are the best practices for using a wood floor sander to refinish hardwood floors?

The best practices for using a wood floor sander to refinish hardwood floors include starting with a coarse grit sandpaper and gradually moving to finer grits, sanding in the direction of the wood grain, keeping the sander moving at all times to avoid creating uneven spots, and wearing protective gear such as a dust mask and goggles. It is also important to properly prepare the floor by cleaning and repairing any damage before sanding.