Use the Easel project to cut out the main body.
This will cut out the left and right side, with the slots for the trays, and the dados for the top and bottom.
With the 0.5" plywood, cut the top and bottom: 11.75″ × 11.25″.
Glue the top and bottoms to the left and right sides.
With the 0.125" MDF, cut a piece 22″ × 12.25″.
Glue and nail to the back of your organizer.
With the 0.25" MDF, cut as many trays you want.
Cut as many center dividers and you need.
These are simple ~10" long strips. Match the height to match the distance between trays / shelves.
One can batch out a trays faster if using a table saw and a jig.
Cut the trays on the table saw in 11.5″ × 11.25″ panels.
Then simply screw or clamp them in place on your machine.
Remove the profile cut from the Easel project and save yourself some time.