Cut four short and two long lengths of 1x2, sized to fit your installation, to frame the decorative end panel for the bed box.
Use a router or router table with a tongue-and-groove bit to rout a groove down the center of all frame pieces.
Use the same router bit to rout a decorative profile on the face of the frame pieces (Image 1).
Re-adjust the cutter blades and form a tongue on the ends of each of the short frame pieces. Cut them two at a time to keep the ends from tearing out.
After cutting, check the fit to be sure the frame pieces mate perfectly. Also check the assembled panel’s dimensions from corner to corner. If the measurements are equal, the assembly is square (Image 2).
When you dry-fit the frames, also measure for the plywood inserts that will go into each frame.
Cut 1/4" plywood to create three "faux" door panels for the decorative end panel. Size the plywood inserts 1/8” smaller in width and length than the dimensions of the frame grooves. This enables the plywood to “float” freely within the frames and allows for natural expansion.
Use glue to assemble the face frames. As you assemble them, insert the plywood sections but do not glue them in place. Check that the assembly is square and allow the glue to dry (Image 3).