Take the measurements of the shelf in your floating shelf kit. You must know how long and how tall it is so you can determine where to install it on your wall.
Mark the location on the wall where you want to install your floating shelf, using chalk. Chalk is easy to see and easy to erase once you complete the project.
Hold your floating shelf brackets against the wall, on the chalk line you drew in Step 2. Mark the positions of the brackets' holes. Set the brackets down with the rest of your supplies.
Drill pilot holes in the bracket hole locations you marked. Pilot holes make it easier to drill the screw when you mount the brackets to the wall. Pilot holes also help protect your wall from damage, especially if you're drilling into a wood wall.
Use the screws included in your floating shelf kit to secure the brackets to the wall. Hold the wall brackets back up in their designated locations and drill screws through the bracket holes and into the walls, using your pre-drilled pilot holes as guides. Insert the appropriate number of screws into each bracket to help ensure your floating shelf will stay securely on the wall.
Slide your floating shelf on the wall brackets, then push the shelf back so it sits flush against the wall. The floating shelf surrounds the wall brackets, so they remain hidden once you push the shelf in place.