Measure the length of the window with measuring tape to find the size of curtain rod needed. Allow an extra 1 to 3 inches on each side of the window and at least 4 inches above the window trim.
Mark the place where each curtain rod bracket should be positioned on each side of the window with a pencil.
Hold the bracket to the wall over the pencil mark. Place a level next to and on top of the bracket to ensure that it is straight.
Mark the location of the bracket's screw holes with a pencil.
Predrill the screw holes with an electric drill or Phillips screwdriver.
Insert drywall anchors into the predrilled holes. Employing anchors is necessary only if screwing the mount directly into drywall. If screwing the mount into the stud, skip this step.
Position the first rod mount over the drywall anchors or predrilled holes. Then use a Phillips screwdriver or electric drill to screw the mounts into the wall.
Repeat the process to screw in the second and, if applicable, third mounts into the wall.
Twist the finials on the end of each rod by hand, if applicable.
Hang the curtain on the rod to complete installation.