Measure the diameter of the feet of your stool. Purchase felt pads that are the same diameter as your stool's feet.
Wipe the feet of the stool down with a rag moistened with rubbing alcohol. Clean off any dust, dirt or debris.
Attach the felt pads to the stools. To attach sticky pads, remove the paper backing from the felt pads and stick them onto the feet of the stool. Make sure that they are centered before you press them on. Some pads come with a small metal attachment that you tap into the rubber foot of the stool with a hammer.
Keep the floor clean with regular sweeping and mopping. Check the felt pads periodically. Change them when they accumulate a heavy layer of dust and debris.