Plywood is made of multiple layers of thin wood (veneers) that have been glued together with a strong adhesive. Putting screws into plywood is not difficult but care should be taken not to split the wood. There are many different types of plywood and screws. This procedure can be used with most combinations.
Put on the safety glasses and place the plywood on a sturdy table or on the floor. If saw horses are available, place the plywood on the two saw horses. The key is to have a stable and steady work surface.
Measure at least 6 inches from the top and side of the piece of plywood. Start from one corner of the plywood and mark an X on that spot with a pencil.
Drill a hole into the X, slowly, using a drill bit that is smaller than the diameter of the screw and the electric drill. Do not drill through the entire piece of plywood.
Hold the 1/2-inch screw with the tip in the drilled hole. Using the Phillips head drill bit and the electric drill, slowly rotate the screw into the hole. Once it is started, increase the speed of the drill until the screw head is flush (even) with the surface of the plywood.
Sand the wood lightly with sandpaper around the screw.
Ensure the drill bit's diameter is not larger than the screw's diameter.
Always wear safety glasses when using power tools.