After trimming the extra paper away, I drew the piece shapes onto the back. Using a ruler, I divided it into quarters both vertically and horitontally to get the piece squares. Then Iused geometrical shapes (both for ease of cutting and for ease of recognition) for for interlocking edges. Using an X-acto knife, I carefully cut out each piece.
The envelope was made from a sheet of red paper using a template found here, and his name was added to the front.
Ready for delivery!