Place the stencil directly on the carpet where the design will be painted. Use the masking tape to secure the stencil to the carpet.
Dip the paintbrush into the paint or stain and wipe off any excess paint. Paint the area of the carpet that is exposed from the stencil. Be sure to press the brush into the fibers of the carpet to ensure an even coat.
Allow the paint or stain to dry completely before removing the stencil. If necessary, paint a second coat over the design while the stencil is still in place. Repeat the entire process to paint the design in another location.