To add support and create compartments, measure and cut one piece of poplar stock to fit the width of the perimeter box.
Place the bottom organizer into the drawer. Mark the height of the organizer on the back of the drawer above the organizer.
Measure and cut the poplar stock using the measurements for the length and width. Nail the top perimeter box together.
Slide the top organizer into the drawer, and replace drawer into cabinet. Fill with utensils and mail.