First, you need to buy a 16" x 20" framed canvas [back of the frame shown below] from any crafts store. Glue a 16" x 20" piece of cork to the front of this framed canvas and let it dry.
This is where all of your leftover batting will come in handy. Wrap a 18" x 22" piece of batting around and staple to the back of the frame. Trim excess batting from the corners.
Sew the quilt top as per the directions in the pattern and center on the front of the board. Pull fabric to the back and staple. For a nice finish, staple a 16" x 20" piece of cardstock to the back of the frame.
xo, L