A sash curtain is an easy way to dress up a narrow window or French door. The sash generally covers the entire length of the window and is gathered at the center with a "sash" or other kind of tie. The key to hanging a sash is to hide the rod and accent the gather. The rods are installed flush to the inside molding of the window or door at the top and bottom, while the ends of the sash, which is longer and wider than the opening, cover the rods and hold the curtain.
Make a small mark 1/2 inch from each side of the corners of the window. Hold one of the mounting brackets with its outside edge along the mark on the side corner of the window frame. Line the bottom of the bracket up with the 1/2-inch mark on the bottom of the same corner.
Mark the frame inside the screw holes with a pencil, making sure to mark the entire opening. Repeat on the opposite side of the window.
Hold the level between the marks on either side of the window to make sure the screw holes line up. Adjust the marks as needed, staying as close to the 1/2-inch mark as possible.
Loose-fit the mounting brackets on both sides of the window using the small hand drill or electric screwdriver. Make sure the screws are all the way in but not tightened. Use the level to make sure the brackets are even.
Tighten the screws to the mounting bracket. Repeat for the other end of the window. When you have mounted all the brackets, thread the sash curtain through both rods and snap the rods into the bracket. Adjust the curtain to cover the rods evenly.