Remove three rubber rings from preserves jars and glue them one on top of the other. Use a rubberized household adhesive commonly known as "goo," and available at hardware stores or department stores. Repeat this four times for a rectangular or square rug. Do it three times for a round rug. Let the rings dry.
Glue the sets of rings to the bottoms of your rug, in the corners. For round rugs, just space the three sets of rings evenly apart towards the edges. The rings act like suction cups to prevent slipping.
Instead of the rings, Place two-sided tape on the back of the rug around the edges. If it still slides a little, place a little more towards the center of the rug.
You also can use bathtub decals, which prevent you from slipping in the tub. Just stick them on the bottom of your rug.