Purchase barrel casters rather than ball casters. Ball casters can cause dents in hardwood floors since all the weight is in one spot, whereas barrel casters evenly distribute the weight.
Lift one edge of the chair and spin the casters. Some twin-wheeled nylon casters require you slide the chair across the floor to move it. This is acceptable for carpeting, but causes scratches and scuffs on hardwood flooring.
Look for soft rubber wheels on the chair caster that spin without difficulty.
Pick soft polyurethane caster wheels for their ability to roll across hardwood floors easily.