Measure the width of your window using a tape measure, including the trim or molding. Add 4 inches to this measurement.
Clamp a piece of 1-inch PVC pipe into a vise.
Measure the total from step 1 along the pipe, and mark the measurement with a pencil.
Wrap a piece of masking tape around the pipe at the pencil mark. This will ensure that the line is perfectly straight.
Cut the pipe along the mark with a hacksaw.
Apply a bead of PVC glue into each end of the pipe, then insert a 1-inch PVC T-plug into each end. Wipe off any excess glue with a paper towel and allow it to dry.
Attach a screw-on decorative knob to each end, screwing them through the PVC T-plugs. If the knobs have blunt screws instead of pointed ones, drill a hole in the center of each T-plug that is slightly smaller than the screw diameter.
Paint the frame as desired.
Screw two curtain brackets to the wall with the included hardware. They should be positioned 4 inches above the window, and the outer edges of the brackets should be 2 inches out from the window, trim or molding.
Thread the frame through your curtain's rings and hang it from the brackets.