When you install curtain holdbacks -- medallions on posts or hook-shaped holdbacks -- within 3 inches of the window's edge, you'll more than likely fasten them to the jack and king studs beneath the drywall, if the home was built according to standard construction practices. You can also install post holdbacks at the top of the window to drape a scarf valance. If the window has trim, you'll need toggle bolts to keep the holdbacks from pulling out of the wall. With your handy do-it-yourself skills, a power drill and bits, a tape measure and the right hardware, this is a project you can do.
Look at the window treatment that covers your windows. If the drapes fall to the floor, you may want to put your metal holdbacks in the middle of the panel or window -- or lower for a long swagged look. Where you place them is a matter of personal preference.
Make a pencil mark on one side of the window where you want to set the curtain holder. Measure from the edge of the window frame to that location. If it's within 3 inches, you should be able to install the curtain holdbacks directly into the wall with long screws. If it's past that, you need to install the curtain holdback with toggle anchor bolts so they do not rip out the drywall with the weight of the curtains.
Measure the location of the curtain holdback from the bottom of the floor on the side you marked and repeat on its opposite side and make a mark. Most curtain holdbacks are installed between 40 to 48 inches up from the floor, but it is a personal choice where you install them.
Hold the curtain hook drawback or medallion post bracket level at the penciled location, and make a mark through the holes for the screws with the pencil. Repeat on the other side.
Make a small pilot hole with the drill and drill bit sized to the fastener if you are installing screws. Attach the screw bit and use the drill on low power to install the screw. Repeat for the other side. Add the medallion hardware as per the manufacturer's instruction, as these come in different varieties. It usually involves attaching the medallion to the bracket by tightening a screw on the side of the bracket's post to keep the medallion in place.
Drill a hole sized to the toggle bolt with a drill bit if you are installing in drywall without a stud behind it. Insert the screw through the hole in the curtain holdback and thread the winged toggle bolt onto its end.
Insert the toggle bolt wings by holding them while they're collapsed through the hole until they open inside the wall. Hold the fastener taut as you screw it in so that the wings stay flat against the inside of the wall.
Place a level on the hook-shaped curtain holdbacks and readjust as necessary to ensure they are level.