Measure 1 1/2" in at each end from both the left and right sides of one of the pieces of wood. Drill two holes; I used a countersink bit so that the screws would sit flat down in the recess.
Hold the drilled 5" x 5" piece of wood upright next to the other piece (base). Insert an awl and penetrate the base.
Paint both wood pieces with the acrylic paint and let dry.
While the paint is drying, cut pieces of paper to fit the pieces of wood - both the front and back, as well as the sides.
Decoupage the paper and cardstock to the wood. Let dry for 15 - 20 minutes before applying a top coat.
To assemble, attach top with two screws into the bottom base using a screwdriver. The base is complete. Repeat with the other side.
Attach the baseballs in place. You can use industrial glue like E-6000 to attach the baseball in place. Personally, I eyeballed where the contact point was and drilled through the upright piece and then screwed the baseball into place.
Attach four self stick rubber pads to both bases before using.