Since drywall alone is not very strong, heavy items need special attention to make sure they stay where you hang them. The best way to safely hang something on a wall is to use a stud finder and use a fastener that goes though the drywall into the stud. If you can’t find a stud, or the stud is not in a location where you want your picture to hang, you can try our favorite method which is to use an Easy Anchor or similar type drywall anchor. These come in packages with the screw in wall anchors and properly sized screws. Follow the directions on the packaging for proper installation. They are available in various sizes depending on the amount of weight you are trying to support.