Place two cubical shelves vertically. These two shelves should have a 36-inch space between them to create a total width of 60 inches.
Attach one 1-by-4 to the front side of the two 12-inch wide cubical shelves. The 1-by-4 should run from the outer end of the left cubical shelf to the outer end of the right cubical shelf. Drive a nail every 4 inches to attach the board to the shelves.
Attach the remaining 1-by-4 to the back side of the shelves in the same manner
Place the 1-inch thick MDF on top of the cubical shelves, lining up the 60-inch sides with the outer edge of the two 1-by-4s and the 38-inch edge with the outer edges of the cubical shelves. Drive one nail every 6 inches around the entire perimeter of the MDF to join the top to the base.
Cover every surface of the craft desk with primer. Use the roller to cover the top of the desk and any large areas. Work primer into hard-to-reach locations with a paintbrush. Allow primer to set for two to four hours.
Cover every surface of the craft desk with paint. Allow the paint to dry for two to four hours and apply a second coat if necessary.