The most recommended grit sequence for floor sanding is to start with a coarse grit such as 36 or 40-grit and then progress through finer grits such as 60, 80, and 100, and finish with 120-grit. This sequence will give your floor an even, smooth surface and will help protect it from scratches and dings.
For sensitive floors such as oak or pine, it is best to start with a lower grit, such as 24 or 30. In general, it is best to sand the floor in the same direction as the grain to ensure a smooth finish.