Cut two boards 2 feet long for the vertical sides. Cut two boards 1 1/2 feet long for the top and base.
Sand all boards by hand with sandpaper or a sanding block; mechanical sanders are not necessary as only minor imperfection are being treated in this stage. Wipe down the boards with a tack cloth.
Lay the base on a flat work surface with the 1 1/2-foot side horizontal. Position the board so that it hangs over 2 to 3 inches over the edge of the table.
Spread a 2-inch strip of glue along the left and right sides of the face grain within 1/4 inch of the edges.
Stand the long boards on top of the sides of the base so that the end grain is in direct contact with the glue. You can turn the pieces on their sides and work horizontally if desired.
Apply glue to the end grain of the vertical boards and place the 1 1/2-foot-long board on top to form a rectangular cuboid.
Place a clamp at each corner of the frame so that the base and the top are pressed together. Wipe off any excess glue with a moist cloth.
Allow the glue to dry overnight.
Fasten the rectangle together with 3- or 4-inch nails. Drive nails into the face grain of the base and the top pieces in a row 1 inch from the side edge and 2 inches from the top and bottom of the piece; the 2-inch gap parallel to the side panel permits space for the casters. Place one nail every 1 to 2 inches.
Remove the clamps.
Flip the frame over so that the base is upright. Screw the casters to the corners of the board with 1 1/2-inch screws. You may use a longer screw where the fastener penetrates the end grain of the side panel.
Fill all holes with wood putty. Dry the piece overnight.
Sand the nightstand. Wipe the piece down with a tack cloth.
Apply two coats of colored varnish to decorate and protect the nightstand. Apply the first coat perpendicular to the grain. Allow the varnish to dry overnight. Apply a second coat with the grain.
Leave the table undisturbed for three days to allow the varnish to begin to cure.