Measure the distance between the two sides in the cabinet or cupboard where the sliding shelf will be installed using the measuring tape. Measure the depth of the cabinet as well. Write both measurements down and subtract 1/2 inch from each of the measurements.
Place the plywood down flat and draw a rectangular shelf using the pencil, ruler and measurements from the previous step. Cut the shelf out with the jigsaw and sandpaper the splinters out. Put the shelf aside for now.
Separate the sliding tracks from one another. Each sliding track has two components. The base piece is the piece of track that is installed in the cabinet and the sliding component is attached to the shelf itself.
Place the level inside the cabinet up against the sides to determine where the sliding shelf will be installed. Keep the sliding shelf low in the cabinet. Make marks on the side of the cabinet using the pencil to indicate where the base component will be installed.
Line one base piece up against one side of the cabinet. Install it using the screws that come with the sliding tracks and the screwdriver. Repeat this step with the opposite side and secondary base piece. Use the level to ensure the tracks are even on the wall and in relation to one another.
Insert the plywood shelf into the cabinet and line it up with the installed base tracks. Make marks on the side of the shelf with the pencil to indicate where the sliding components need to be installed.
Install the sliding tracks on the sides on the shelf using the screws and the screwdriver. Use the marks as guidance. Place the shelf at an angle when connecting the sliding pieces with the base tracks. Push the shelf into the tracks until it clicks. Pull the shelf in and out to ensure it is installed properly.