Instructions:
Lay the socks flat on your work surface so that the bottom side is up. Now, simply use the puffy fabric paint to make dots, lines, or other shapes on the bottom of the sock. This will transform the ordinary socks into socks with a non-skid bottom.

Depending on how thick the paint is applied, the designs may take several hours to dry! Once the bottoms are dry, you can decorate the top of the sock if you want. Wear and enjoy.

or check out video below

Here is a link that might be useful: non-slip socks