A quick and easy way to make the soles of your socks or slippers non-skid is to use a product from the hardware store. “Plasti-dip” is a paint like substance marketed for making the handles of tools less slippery. For socks, use a foam paint brush, and daub the Plastidip on to the soles. No more skidding on hardwood or tile floors. It retails for between $6-8.
For a spray on solution, the same company also sells an aerosol package. Seems like the daub on method would be easier to control, though.