Determine the height and location of the wall shelf. Measure from the floor and place a mark on the wall with the pencil.
Measure from the top of the shelf to the centerline of the mounting bracket located on the back of the shelf. Place a pencil mark below the height mark for the location of the mounting screw. Use the stud finder to determine if there is a stud located behind the mark. Secure the screw accordingly. If a stud is present, drive a wood screw through the drywall and into the stud. Use a hollow wall anchor to secure the screw to the wall if no stud is present. Follow the manufacturer's installation instructions for the hollow wall anchor. With either method of securing the screw, leave the screw head 3/16-inch away from the surface of the wall.
Align the slotted hole on the decorative wall shelf's mounting bracket with the screw secured to the wall. Lay the shelf against the wall. Slide the shelf down until the screw locks into the mounting bracket.
Orient the shelf so the top edge is parallel to the floor. Set the 4-foot level on top of the shelf. Adjust the wall shelf until it is level. Place a pencil mark at the top edge of the shelf. Set aside the 4-foot level. Remove the wall shelf and set it aside. Measure down from the top mark of the shelf. Place a mark for the location of the second mounting screw. Use the stud finder to see if a stud is located behind the mark. Insert the second screw into the drywall. Leave the screw head 3/16-inch away from the surface of the drywall.
Re-align the shelf with the screws located in the wall. Slide the shelf onto the mounting screws. If there is a gap where the shelf meets the wall, remove the shelf. Tighten the screws with the Phillips screwdriver. Re-hang the shelf. Repeat the process of tightening the screw till the gap against the wall is closed.