Dust the baseboards with a clean cloth. Vacuum the carpet next to the baseboards using a brush attachment.
Apply painter's tape along the wall on the top side of the entire baseboard.
Lay dropcloths or old sheets on the carpet and next to the baseboards.
Place a thin piece of cardboard under the baseboard. The cardboard sits between the carpet and the baseboard.
Dip an angled sage brush into the paint, and brush back and forth over the baseboard. Paint the bottom of the baseboard, allowing the paint to deposit onto the cardboard. Remove the cardboard when finished and place into the next section of the baseboard. As the piece of cardboard becomes saturated with paint, replace with a new one. Continue painting the remaining baseboard until finished.