Wash your stairs with soapy water and a scrub brush to remove any dirt and debris. Allow the stairs to dry.
Measure 3 inches in from each side of the stairs and apply low-tack painters tape, leaving only the middle of the stairs uncovered. This will protect the sides from paint and create the illusion of a runner going down the middle of the stairs.
Apply a coat of primer to the stairs with a brush or roller. Use a primer that is designed for the material that your stairs are made of, be it wood, metal or stone.
Allow the primer to dry completely.
Apply a coat of paint onto the primer. The paint should be the main color of your rug. Allow the paint to dry.
Use stencils to add designs to the faux rug with other colors of paint. You can also paint designs freehand, but a stencil will provide more uniform results. Allow the paint to dry.
Carefully remove the painters tape.
Create tassels along the sides of the rug using a small brush to paint 1-inch lines coming from both sides of the rug. Use a light colored paint for this. You can also paint small circles every inch with lines extending from them for the illusion of knotted tassels.
Brush a coat of clear urethane sealer onto the stairs to protect them.